Industrial applications have unique power needs and the choice of battery is important. While consumer products demand high energy density to obtain slim and elegant designs, industry focuses on durability and reliability. Industrial batteries are commonly bulkier than those used in consumer products but achieve a longer service life.
Batteries are electro-chemical devices that convert higher-level active materials into an alternate state during discharge. The speed of such transaction determines the load characteristics of a battery. Also referred to as concentration polarization, the nickel and lithium-based batteries are superior to lead-based batteries in reaction speed. This attribute reflects in good load characteristics.
Discharge loads range from a low and steady current flow of a flashlight to intermittent high current bursts in a power tool, to sharp current pulses on digital communications equipment, laptops and cameras. In this paper we evaluate how the various battery chemistries perform in a given application.
What's the best battery for video cameras?
Nickel-cadmium batteries continue to power a large percentage of professional cameras. This battery provided reliable service and performs well at low temperature. nickel-cadmium is one of the most enduring batteries in terms of service life but has only moderate energy density and needs a periodic full discharge.
The need for longer runtimes is causing a switch to nickel-metal-hydride. This battery offers up to 50% more energy than nickel-cadmium. However, the high current spikes drawn by digital cameras have a negative affect and the nickel-metal-hydride dell inspiron 1520 battery suffers from short service life.
There is a trend towards lithium-ion. Among rechargeables, this chemistry has the highest energy density and is lightweight. A steep price tag and the inability to provide high currents are negatives.
The 18650 cylindrical lithium-ion cell offers the most economical power source. "18" defines the cell's diameter in millimeters and "650" the length. No other lithium-ion cell, including prismatic or polymer types, offers a similar low cost-per-watt ratio.
Over the years, several cell versions of 18650 cells with different Ah ratings have emerged, ranging from 1.8Ah to well above 2Ah. The cells with moderate capacities offer better temperature performance, enable higher currents and provide a longer service life than the souped up versions.
The typical 18650 for industrial use is rated at 2Ah at 3.60 volts. Four cells are connected in series to obtain the roughly 15 volts needed for the cameras. Paralleling the cells increases the current handling by about 2A per cell. Three cells in parallel would provide about 6A of continuous power. Four cells in series and three in parallel is a practical limit for the 18650 system.
Lithium-ion requires a protection circuit to provide safe operations under all circumstances. Each cell in series is protected against voltage peaks and dips. In addition, the protection circuit limits each cell to a current about 2A. Even if paralleled, the current of a lithium-ion pack is not high enough to drive digital cameras requiring 10 to 15A peak current. Tests conducted at Cadex Electronics have shown that the 18650 allows short current peaks above the 2A/cell limit. This would allow the use of lithium-ion on digital cameras, provided the current bursts are limited to only a few seconds.
What's the best battery for still cameras?
The power requirement of a professional digital camera is sporadic in nature. Much battery power is needed to take snapshots, some with a powerful flash. To view the photo, the backlit color display draws additional power. Transmitting a high-resolution image over the air depletes another portion of the energy reserve.
Most non-professional cameras use a primary lithium hp battery. This battery type provides the highest energy density but cannot be recharged. This is a major drawback for professional use. Rechargeable batteries are the answer and lithium-ion fits the bill but faces similar challenges to the video cameras.
What is the best battery for medical devices?
One of the most energy-hungry portable medical devices is the heart defibrillator. The battery draws in excess of 10 amperes during preparation stages. Several shocks may be needed to get the patient's heart going again. The battery must not hamper the best possible patient care.
Most defibrillators are powered by nickel-cadmium. nickel-metal-hydride is also being used but there is concern of short service life. In a recent study, however, it was observed that a defibrillator battery cycles far less than expected. Instead of the anticipated 200 cycles after two years of seemingly heavy use, less than 60 cycles had been delivered on the battery examined. 'Smart' battery technology makes such information possible. With fewer cycles needed, the switch to higher energy-dense batteries becomes a practical alternative.
Sealed lead-acid batteries are often used to power defibrillators intended for standby mode. Although bulky and heavy, the Lead-acid has a low self-discharge and can be kept in prolonged ready mode without the need to recharge. Lead-acid performs well on high current spurts. During the rest periods the dell inspiron 9400 battery disperses the depleted acid concentrations back into the electrode plate. Lead-acid would not be suitable for a sustained high load.
The medical industry is moving towards lithium-ion. The robust and economical 18650 cells make this possible. The short but high current spurts needed for defibrillators are still a challenge. Paralleling the cells and adding current-limiting circuits that allow short spikes of high current will help overcome this hurdle.
What is the best battery for power tools?
Power tools require up to 50 amperes of current and operate in an unfriendly environment. The tool must perform at sub zero temperatures and endure in high heat. The batteries must also withstand shock and vibration.
Most power tools are equipped with nickel-cadmium batteries. nickel-metal-hydride has been tried with limited success. Longevity is a problem but new designs have improved. lithium-ion is too delicate and could not provide the high amperage. Lead-acid is too bulky and lacks persistent power delivery. The power tool has simply no suitable alternatives to the rugged and hard-working nickel-cadmium.
In an attempt to pack more energy into power tools, the power tool battery voltage is increased. Because of heavy current and application at low temperatures, cell matching is important. Cell matching becomes more critical as the number of cell connected in series increases. A weak cell holds less capacity and is discharged more quickly than the strong ones. This imbalance causes cell reversal on the weak cell if the battery is discharged at high current below 1V/cell. An electrical short occurs in the weak cell if exposed to reverse current and the pack needs to be replaced. The higher the battery voltage, the more likely will a weak cell get damaged.
2011年4月29日星期五
2011年4月25日星期一
Advanced Battery Analyzers
How are batteries checked and serviced? This article describes the advancements of the modern battery analyzer and explains how these instruments are used in the industry. While organizations such as public safety have been using battery analyzers for the last two decades to restore and prolong nickel-cadmium batteries, analyzers have made their way also into the cell phone, portable computing, medical and defense markets. The early models were impractical and did not adapt well to changing battery chemistries. In addition, the analyzers provided limited service and did not offer the quick test results and restoration capabilities customers demand today.
The last few years have brought a rebirth of the battery analyzer. With the move from the high-maintenance nickel-based batteries to the maintenance-free lithium-based packs, the duty of a battery analyzer is changing from life-extending cycling to rapid testing and boosting.
Cadex solved the battery interface issue with the custom adapters for common batteries and the universal adapters for specialty packs. The custom adapters are the easiest to use and provide the most accurate test results. User-programmable cables accommodate larger batteries or assist when no adapter is on hand. Smaller batteries can be serviced with the Cadex FlexArm™. Two contact probes mounted on flexible arms provide the connection when lowered to the battery terminals. Magnetic guides keep the battery in position and a temperature sensor safeguards the battery.
The Cadex adapters contain a memory chip that configures the analyzer to the correct setting. Each adapter stores 10 battery configuration codes to service 10 different battery types. The parameters can be edited with a few keystrokes on the analyzer's keypad.
Many modern analyzers also offer battery rapid test programs. This often requires entering the battery voltage and rating (in mAh). To obtain accurate readings, a battery-specific matrix may also be required. The Cadex QuickTest™ stores the matrix in the battery adapter, together with the configuration code. Installing the adapter sets the analyzer to the correct parameters, transparent to the user.
With the Cadex system, the matrix is commonly included when purchasing the adapter. If missing, scanning several batteries with various state-of-health conditions creates the matrix. The test time is 3 minutes and requires a charge level of 20-90%. If outside this range, the analyzer automatically applies a brief charge or discharge.
Many batteries are discarded, even when restoration is possible. Cell phone dealers have confirmed that 80-90% of returned mobile phone batteries can be repaired with a battery analyzer. However, most dealers are not equipped to handle the influx of warranty batteries and the packs are returned to the manufacturers for replacement or are discarded. Rapid test enables checking the battery while the customer waits. Minor toshiba pa3450u-1brs battery problems can be corrected on the spot.
A typical failure of lithium-ion batteries is excessive low discharge. If discharged below 2.5 volts per cell, the internal safety circuit deactivates and the battery no longer accepts charge with a regular charger. An excessive low discharge can occur if the battery is not recharged for some time after a full discharge through extensive use.
The Cadex battery analyzers feature Boost, a program, which reactivates batteries that appear dead. Boost works by applying a gentle current to the battery to re-energize the safety circuit and raise the cell voltage. After reaching the operating voltage, the battery can be charged and tested normally. Boosted batteries perform flawlessly as long as a repeat deep discharge is avoided.
Labeling the batteries with service date and test results is self-governing in the sense that the user only picks a properly labeled toshiba pa3819u-1brs battery and has recently been serviced. Batteries with past due service date are segregated for service. With such a system, the user has full confidence that the battery will last through the shift, with energy to spare. Weak batteries are weeded out.
The last few years have brought a rebirth of the battery analyzer. With the move from the high-maintenance nickel-based batteries to the maintenance-free lithium-based packs, the duty of a battery analyzer is changing from life-extending cycling to rapid testing and boosting.
Fixed current analyzers
There are two basic types of battery analyzers: the fixed current and programmable versions. Fixed current units are the lower priced of the two, and charge and discharge a toshiba satellite a350 battery at a preset current of about 600mA. Smaller batteries get serviced reasonably fast but larger batteries are slow. The service time of an 1800mAh battery is three times that of a 600mAh pack. The capacity readout is in mAh and reflects the length of discharge. The fixed-current analyzers are the predecessors of the programmable units.Programmable analyzers
The programmable analyzers allow servicing the battery against preset parameters. The charge and discharge currents are adjusted according to the battery rating, and the voltage is set to flag batteries with incorrect voltages. These analyzers provide more accurate readings and enable higher battery throughput than fixed current units. In addition, programmable analyzers are better suited to service new battery systems and have proven to be more effective in restoring weak batteries. The Cadex C7000-Series are such programmable toshiba satellite a200 battery analyzers.Battery adapters
Interfacing the batteries has always been a challenge with battery analyzers. Technicians have invented contraptions with springs and levers so complicated that only they themselves are able to operate. Everybody else stays away from them of fear.Cadex solved the battery interface issue with the custom adapters for common batteries and the universal adapters for specialty packs. The custom adapters are the easiest to use and provide the most accurate test results. User-programmable cables accommodate larger batteries or assist when no adapter is on hand. Smaller batteries can be serviced with the Cadex FlexArm™. Two contact probes mounted on flexible arms provide the connection when lowered to the battery terminals. Magnetic guides keep the battery in position and a temperature sensor safeguards the battery.
The Cadex adapters contain a memory chip that configures the analyzer to the correct setting. Each adapter stores 10 battery configuration codes to service 10 different battery types. The parameters can be edited with a few keystrokes on the analyzer's keypad.
Service programs
Advanced battery analyzers are capable of evaluating toshiba pa3594u-1brs battery conditions and implementing corrective service to restore weak performance. The Cadex system, for example, automatically applies a recondition cycle to nickel-based packs if a user-selected target capacity cannot be reached. Other programs include Prime to prepare a new battery for field use, Charge to allow fast-charge and Custom to apply unique cycles composed of charge, discharge, recondition, trickle charge or any combination, including rest periods and repeats.Many modern analyzers also offer battery rapid test programs. This often requires entering the battery voltage and rating (in mAh). To obtain accurate readings, a battery-specific matrix may also be required. The Cadex QuickTest™ stores the matrix in the battery adapter, together with the configuration code. Installing the adapter sets the analyzer to the correct parameters, transparent to the user.
With the Cadex system, the matrix is commonly included when purchasing the adapter. If missing, scanning several batteries with various state-of-health conditions creates the matrix. The test time is 3 minutes and requires a charge level of 20-90%. If outside this range, the analyzer automatically applies a brief charge or discharge.
Many batteries are discarded, even when restoration is possible. Cell phone dealers have confirmed that 80-90% of returned mobile phone batteries can be repaired with a battery analyzer. However, most dealers are not equipped to handle the influx of warranty batteries and the packs are returned to the manufacturers for replacement or are discarded. Rapid test enables checking the battery while the customer waits. Minor toshiba pa3450u-1brs battery problems can be corrected on the spot.
A typical failure of lithium-ion batteries is excessive low discharge. If discharged below 2.5 volts per cell, the internal safety circuit deactivates and the battery no longer accepts charge with a regular charger. An excessive low discharge can occur if the battery is not recharged for some time after a full discharge through extensive use.
The Cadex battery analyzers feature Boost, a program, which reactivates batteries that appear dead. Boost works by applying a gentle current to the battery to re-energize the safety circuit and raise the cell voltage. After reaching the operating voltage, the battery can be charged and tested normally. Boosted batteries perform flawlessly as long as a repeat deep discharge is avoided.
Printing
Most analyzers are capable of printing service reports and battery labels. This feature simplifies maintenance, especially in a fleet environment where the operators must observe periodic service requirements. Printed reports also benefit customer service staff and engineers.Labeling the batteries with service date and test results is self-governing in the sense that the user only picks a properly labeled toshiba pa3819u-1brs battery and has recently been serviced. Batteries with past due service date are segregated for service. With such a system, the user has full confidence that the battery will last through the shift, with energy to spare. Weak batteries are weeded out.
2011年4月20日星期三
How Notebook PC to make the battery last longer
A laptop that comes with a battery such as dell inspiron 9400 battery for driving the body. Unlike batteries and battery, usually accounts for 10 percent of the unit price from 20% in the prices of its major models only. Such batteries can, leave them in the use of desk UPS (uninterruptible power supply) in addition to use as a instead of just a useless treasure, if you buy in bulk and companies to buy in order to hold down costs without battery Sometimes it seems like.
Would in some things and less about an hour battery life even when used in maple place unique laptop, AC a lot of people move with the adapter, even to get aware of the position of the battery more , especially in portable applications with battery briefly very important.
As mentioned previously, one million laptop batteries in the very expensive things cheap, with prices as there are things they can buy low-cost desktop PC with a high-capacity battery. Tens of minutes driving time of short, long or 10 hours of combined battery capacity, on average is about 2 hours. Better battery life in the catalog, "one to three hours," but things are written so that if you use these three hours is not a good two hours, I normally just over an hour Using Mashou.
Batteries used in notebook computers can be classified into several types such as in alkaline batteries and manganese.
As the laptop battery such as dell inspiron 1520 battery for almost obsolete for years, not only the secondary battery from the old laptop (used to recharge the battery) has been used as a long time. There was observed in memory when the charge is not fully discharged state.
Such as secondary batteries are commonly used. Low-cost laptops are often used to lower costs. A memory effect.
Batteries used in portable devices ranging from mobile laptops. For users with no memory effect, so light can be used conveniently. Special attention should be made so that material could ignite and rough handling. In general use I have not even worry too much. Recently, polymer electrolyte (polymer), light shape even more freedom to use, "Richiumuporimabatteri" has been adopted because some models appeared.
Rechargeable battery has a life expectancy is generally less time or it can be used hundreds of times used, this is the same for your laptop battery. The notebook computer battery is removable and may trouble releasing. If the portable notebook, and Unplug the internal battery in the battery itself can easily replace it yourself is difficult when it becomes available because the battery is bad, it becomes treated as fixed. In this case, it takes both time and cost considerably. It is useful to think of the future and inexpensive for you to choose models with built-in dell latitude d600 battery for easy removal if anything, can be difficult to obtain a replacement battery after a few years after the release of the model, such as when a minor model There is also careful with the neighborhood.
In order to preserve the battery, if the batteries have memory effect, better to charge the end-use, if you care even overcharge and over discharge, like a trick and this seems to be small. If you have more than one batteryn for example dell battery is no problem as I use every other week, AC tie would leave even less power is unquestionable. Battery is degraded in anyway even with hundreds of care may be better not too nervous.
Would in some things and less about an hour battery life even when used in maple place unique laptop, AC a lot of people move with the adapter, even to get aware of the position of the battery more , especially in portable applications with battery briefly very important.
As mentioned previously, one million laptop batteries in the very expensive things cheap, with prices as there are things they can buy low-cost desktop PC with a high-capacity battery. Tens of minutes driving time of short, long or 10 hours of combined battery capacity, on average is about 2 hours. Better battery life in the catalog, "one to three hours," but things are written so that if you use these three hours is not a good two hours, I normally just over an hour Using Mashou.
Batteries used in notebook computers can be classified into several types such as in alkaline batteries and manganese.
As the laptop battery such as dell inspiron 1520 battery for almost obsolete for years, not only the secondary battery from the old laptop (used to recharge the battery) has been used as a long time. There was observed in memory when the charge is not fully discharged state.
Such as secondary batteries are commonly used. Low-cost laptops are often used to lower costs. A memory effect.
Batteries used in portable devices ranging from mobile laptops. For users with no memory effect, so light can be used conveniently. Special attention should be made so that material could ignite and rough handling. In general use I have not even worry too much. Recently, polymer electrolyte (polymer), light shape even more freedom to use, "Richiumuporimabatteri" has been adopted because some models appeared.
Rechargeable battery has a life expectancy is generally less time or it can be used hundreds of times used, this is the same for your laptop battery. The notebook computer battery is removable and may trouble releasing. If the portable notebook, and Unplug the internal battery in the battery itself can easily replace it yourself is difficult when it becomes available because the battery is bad, it becomes treated as fixed. In this case, it takes both time and cost considerably. It is useful to think of the future and inexpensive for you to choose models with built-in dell latitude d600 battery for easy removal if anything, can be difficult to obtain a replacement battery after a few years after the release of the model, such as when a minor model There is also careful with the neighborhood.
In order to preserve the battery, if the batteries have memory effect, better to charge the end-use, if you care even overcharge and over discharge, like a trick and this seems to be small. If you have more than one batteryn for example dell battery is no problem as I use every other week, AC tie would leave even less power is unquestionable. Battery is degraded in anyway even with hundreds of care may be better not too nervous.
2011年4月17日星期日
Renewable Energy News – Printed Battery Technology Unveiled
a technology similar to printing solar cells, Xerox’s Palo Alto Research Center (PARC) has developed a process to “print” batteries with the potential for far more energy storage capacity than lithium ion batteries. Metal air batteries, such as the acer extensa 5220 battery, have the potential to to provide more energy capacity than lithium ion batteries, however this is dependent on the development of air cathodes that support the power density in order for it to be viable in applications where economy, space and weight are major issues – such as electric vehicles.
PARC says it has developed a process using co-extrusion printing to deposit thick films of functional acer aspire 5920 battery materials onto substrates, which provides up to10 times the air-breathing surface area of conventional electrodes. The pastes of functional materials can contain water-repelling materials such as Teflon interleaved with hydrophilic (“water-loving”) electro-catalyst material.
The deposition can be as narrow as several microns wide and as high as several hundred microns.
PARC is interested in further developing the technology with commercialisation partners in the acer aspire 5536 battery and fuel cell industries or in the materials or equipment markets that service the sector.
PARC has a long history of technology innovation and research, spanning back over 40 years. The company is also behind the second generation of solar concentrators such as those used in the solar farm at Alice Springs airport, which was the first solar electricity generation facility of its kind in the southern hemisphere.
PARC also invented “electronic reusable paper” in 2000, a thin, flexible material that can display graphics and text when an electric charge is applied to it.
PARC says it has developed a process using co-extrusion printing to deposit thick films of functional acer aspire 5920 battery materials onto substrates, which provides up to10 times the air-breathing surface area of conventional electrodes. The pastes of functional materials can contain water-repelling materials such as Teflon interleaved with hydrophilic (“water-loving”) electro-catalyst material.
The deposition can be as narrow as several microns wide and as high as several hundred microns.
PARC is interested in further developing the technology with commercialisation partners in the acer aspire 5536 battery and fuel cell industries or in the materials or equipment markets that service the sector.
PARC has a long history of technology innovation and research, spanning back over 40 years. The company is also behind the second generation of solar concentrators such as those used in the solar farm at Alice Springs airport, which was the first solar electricity generation facility of its kind in the southern hemisphere.
PARC also invented “electronic reusable paper” in 2000, a thin, flexible material that can display graphics and text when an electric charge is applied to it.
2011年4月10日星期日
New Lead Acid Systems
Lead acid batteries continue to hold a leading position, especially in wheeled mobility and stationary applications. This strong market appeal entices manufacturers to explore ways to make the batteries better. Improvements have been made and some claims are so promising that one questions the trustworthiness. It is no secret that researchers prefer publishing the positive attributes while keeping the negatives under wraps. The following information on lead acid developments was obtained from available printed resources at the time of writing.
Firefly Energy
The composite plate material of the Firefly Energy battery is based on a lead acid variant that is lighter, longer living and has higher active material utilization than current lead acid systems. The battery includes foam electrodes for the negative plates, which gives it a performance that is comparable to NiMH but at lower manufacturing costs. Design concerns include microtubule blockage through crystal growth during low charge conditions. In addition, crystal expansion causes a reduction of the surface area, which will result in lower capacity with aging. Pricing is also a concern. It currently costs about $450 to manufacture a Firefly battery as opposed to $150 for a regular lead acid version. Firefly Energy is a spin-off of Caterpillar and went into bankruptcy in 2010.
Altraverda Bipolar
Similar to the Firefly Energy battery, the Altraverda battery is based on lead. It uses a proprietary titanium sub-oxide ceramic structure, called Ebonex®, for the grid and an AGM separator. The un-pasted plate contains Ebonex® particles in a polymer matrix that holds a thin lead alloy foil on the external surfaces. With 50–60Wh/kg, the specific energy is about one-third larger than regular lead acid and is comparable with NiCd. Based in the UK, Altraverda works with East Penn in the USA, and the battery is well suited for higher voltage applications.
Axion Powe
The Axion Power e3 Supercell is a hybrid battery/ultracapacitor in which the positive electrode consists of standard lead dioxide and the negative electrode is activated carbon, while maintaining an assembly process that is similar to lead acid. The Axion Power battery offers faster recharge times and longer cycle life on repeated deep discharges than what is possible with regular lead acid systems. This opens the door for the start-stop application in micro-hybrid cars. The lead-carbon combination of the Axion Power battery lowers the lead content on the negative plate, which results in a weight reduction of 30 percent compared to a regular lead acid. This, however, also lowers the specific energy to 15–25Wh/kg instead of 30–50Wh/kg, which a regular lead acid battery normally provides.
CSIRO Ultrabattery
The CSIRO Ultrabattery combines an asymmetric ultracapacitor and a lead acid battery in each cell. The capacitor enhances the power and lifetime of the battery by acting as a buffer during charging and discharging, prolonging the lifetime by a factor of four over customary lead acid systems and producing 50 percent more power. The manufacturer also claims that the battery is 70 percent cheaper to produce than current hybrid electric vehicle (HEV) batteries. CSIRO batteries are undergoing road trials in a Honda Insight HEV and show good results. Furukawa Battery in Japan licensed the technology. The CSIRO battery is also being tested for start-stop applications in micro-hybrid cars to replace the lead acid starter battery. This battery promises extended life when exposed to frequent start-stop conditions and is able to take a fast charge.
EEStor
This is the mystery battery/ultracapacitor combination that receives much media attention. The battery is based on a modified barium titanate ceramic powder and claims a specific energy of up to 280Wh/kg, higher than lithium-ion. The company is very secretive about their invention and releases only limited information. Some of their astonishing claims are: One-tenth of the weight of a NiMH battery in a hybrid application, no deep-cycle wear-down, three- to six-minute charge time, no hazardous material, similar manufacturing costs to lead acid, and a self-discharge that is only 0.02 percent per month, a fraction of that of lead acid and Li-ion.
Firefly Energy
The composite plate material of the Firefly Energy battery is based on a lead acid variant that is lighter, longer living and has higher active material utilization than current lead acid systems. The battery includes foam electrodes for the negative plates, which gives it a performance that is comparable to NiMH but at lower manufacturing costs. Design concerns include microtubule blockage through crystal growth during low charge conditions. In addition, crystal expansion causes a reduction of the surface area, which will result in lower capacity with aging. Pricing is also a concern. It currently costs about $450 to manufacture a Firefly battery as opposed to $150 for a regular lead acid version. Firefly Energy is a spin-off of Caterpillar and went into bankruptcy in 2010.
Altraverda Bipolar
Similar to the Firefly Energy battery, the Altraverda battery is based on lead. It uses a proprietary titanium sub-oxide ceramic structure, called Ebonex®, for the grid and an AGM separator. The un-pasted plate contains Ebonex® particles in a polymer matrix that holds a thin lead alloy foil on the external surfaces. With 50–60Wh/kg, the specific energy is about one-third larger than regular lead acid and is comparable with NiCd. Based in the UK, Altraverda works with East Penn in the USA, and the battery is well suited for higher voltage applications.
Axion Powe
The Axion Power e3 Supercell is a hybrid battery/ultracapacitor in which the positive electrode consists of standard lead dioxide and the negative electrode is activated carbon, while maintaining an assembly process that is similar to lead acid. The Axion Power battery offers faster recharge times and longer cycle life on repeated deep discharges than what is possible with regular lead acid systems. This opens the door for the start-stop application in micro-hybrid cars. The lead-carbon combination of the Axion Power battery lowers the lead content on the negative plate, which results in a weight reduction of 30 percent compared to a regular lead acid. This, however, also lowers the specific energy to 15–25Wh/kg instead of 30–50Wh/kg, which a regular lead acid battery normally provides.
CSIRO Ultrabattery
The CSIRO Ultrabattery combines an asymmetric ultracapacitor and a lead acid battery in each cell. The capacitor enhances the power and lifetime of the battery by acting as a buffer during charging and discharging, prolonging the lifetime by a factor of four over customary lead acid systems and producing 50 percent more power. The manufacturer also claims that the battery is 70 percent cheaper to produce than current hybrid electric vehicle (HEV) batteries. CSIRO batteries are undergoing road trials in a Honda Insight HEV and show good results. Furukawa Battery in Japan licensed the technology. The CSIRO battery is also being tested for start-stop applications in micro-hybrid cars to replace the lead acid starter battery. This battery promises extended life when exposed to frequent start-stop conditions and is able to take a fast charge.
EEStor
This is the mystery battery/ultracapacitor combination that receives much media attention. The battery is based on a modified barium titanate ceramic powder and claims a specific energy of up to 280Wh/kg, higher than lithium-ion. The company is very secretive about their invention and releases only limited information. Some of their astonishing claims are: One-tenth of the weight of a NiMH battery in a hybrid application, no deep-cycle wear-down, three- to six-minute charge time, no hazardous material, similar manufacturing costs to lead acid, and a self-discharge that is only 0.02 percent per month, a fraction of that of lead acid and Li-ion.
2011年4月7日星期四
Laptop and Battery by Shane Sparks
Professors trade stories about seizing the cell phones of students who text during class or whose tones sound during a lecture.
Frank J. Rybicki, assistant professor of mass media at Valdosta State University, did the equivalent last week when he shut the laptop of a student who was allegedly web surfing as opposed to taking notes. She filed a complaint (reportedly about a finger or fingers that were hurt when he shut the laptop) and the university’s police arrested him on a charge of battery. The Georgia institution suspended his teaching duties there, although not his pay.
Reached on the phone, Rybicki confirmed his arrest and suspension, and said that he had been told by the university not to answer questions about the incident. He did say that the article and comments in the student newspaper, The Spectator, were accurate. That article quoted students who saw the incident as saying that Rybicki closed the laptop amid an argument with the student over his view that she had been on websites not related to the course.
The article also quoted students of Rybicki as saying that they were concerned that an outstanding professor had been arrested and might have his career disrupted. (Rybicki does not have tenure.)
Comments on the site said that the student had been warned to stop surfing the web and had ignored the professor. Generally, the comments were supportive of the professor and critical of the student. “Arrested for dell battery. For closing a laptop? Did it break the students fingers or something? I was thinking he hit a student with a computer. Simply closing it may be a little trivial to ruin a man’s entire life over don’t ya think?” said one comment.
The comments from those saying that they were in class suggested doubt about the extent of the injuries to the student’s fingers and surprise that the incident had led to an arrest. Another comment said: “If this teacher shut the laptop so hard that her arms were somehow mangled, fine … but seriously, she had PLENTY … PLENTY of other options. A. Don’t be so rude in a classroom. B. If you are going to play on your laptop … either don’t take the laptop(laptop battery) to class, or don’t take yourself to class. C. Do what the teacher says for half a second; he/she probably knows more than you do so grow up and take some responsibilities; College isn’t another episode of High School where you can get away with being a distraction; some people here WANT to learn, if you don’t care, … then get out! Or at least be somewhat polite.”
While he declined to discuss the incident specifically, Rybicki did answer a few questions. Asked if students shouldn’t look at non-class websites while in class, he said that was “pretty obvious.” Asked if he had ever caused physical harm to any student, he said “absolutely not, never.”
Several students who were in the class said that they were told by the university not to discuss the incident. The head of the Faculty Senate referred all questions to the university’s spokeswoman, Thressea H. Boyd. Via e-mail, Boyd said, “The university is investigating an incident involving a faculty member and this matter will be processed through the appropriate legal channels. In terms of class instruction, modifications have been made. All employees are expected to perform their obligations and responsibilities in a professional manner.”
As to university policy on laptop use in class, she said that “the use of computers during classroom instruction is within the discretion of each professor at the university.”
Samuel Logan, a Valdosta State student who was not in the course, but who has taken other classes with Rybicki, said via e-mail that he admired Rybicki. “He cares about his students and our grades, always making sure we do our best.” As for what reportedly happened in class, Logan said that an arrest “was not justified because he is a great teacher and she was on Facebook, when we know not to be on other sites while the teacher is teaching.”
2011年3月16日星期三
Can batteries be restored?
Battery users and entrepreneurs often ask, “Can batteries be restored?” The answer is, “It depends.” Most battery failures are permanent and cannot be repaired, but there are exceptions. Sulfation on lead acid batteries can be removed if caught in time; crystalline formation, also known as “memory,” on nickel-cadmium can be dissolved through deep-cycling. Read more about Memory: Myth or Fact?, and “sleeping” lithium-ion packs can be boosted if they have been over-discharged. Read more about Safety circuits for modern batteries.
Permanent battery defects include high internal resistance, elevated self-discharge, electrical short and capacity fade. Poorly designed chargers, exposure to excess heat, harsh charge and discharge cycles, and inappropriate storage contribute to early aging. Let’s examine the cause of these non-correctable battery problems and explore what we can do to minimize them.
Let’s look at what a weak cell does in a pack that is strung together with strong ones. The weak cell holds less capacity and is discharged more quickly than the strong brothers. Going empty first, the strong brothers overrun this feeble sibling and the resulting current on a continued discharge pushes the weak cell into reverse polarity. Nickel-cadmium can tolerate a reverse voltage of minus 0.2V and a reverse current of a few milliamps, but exceeding this level will cause a permanent electrical short. On charge, the weak cell reaches full charge first and it goes into heat-generating over-charge while the strong brothers still accept charge and stay cool. The low cell experiences a disadvantage on both charge and discharge. It continues to weaken until finally giving up the struggle.
The capacity tolerance between cells in an industrial battery should be +/– 2.5 percent. High-voltage packs designed for heavy loads and wide adverse temperature ranges should have lower tolerances. There is a strong correlation between cell balance and longevity.
Li-ion cells share similar deficiencies with nickel-based systems and need management. The mandatory protection circuit supervises the serially connected cells by clamping the voltage when exceeding 4.25 and 4.35V on charge, and disconnecting the pack from discharge when the weakest cell drops to between 2.50 and 2.80V/cell. This prevents the stronger cells from pushing the depleted cell into reverse polarization. The protection circuit acts like a guardian angel that shields the weaker siblings from being bullied by the stronger brothers. This may be help to explain why Li-ion packs for power tools last longer than nickel-based batteries, which normally do not have a protection circuit.
The capacity of quality Li-ion cells is consistent and the self-discharge is low. A problem arises when the cells exhibit a discrepancy in self-discharge. This can be attributed to lower-quality cells or high-temperature spots in a large automotive battery, which hastens aging. Balancing is required and there are two methods: Passive balancing bleeds the high-voltage cells; active balancing shuttles the extra charge from higher-voltage cells to the lower-voltage cells without burning the energy. Active balancing is the preferred method on EVs.
With use and time all batteries become mismatched, and this also applies to lead acid. Shorted cells and those having high self-discharge are a common cause of cell imbalance and lead to subsequent failure. Manufacturers of golf cars, aerial work platforms, floor scrubbers and other battery-powered vehicles recommend an equalizing charge of 3–4 hours if the voltage difference between the cells is greater than +/– 0.10V, or if the specific gravity varies more than 10 points (0.010 on the SG scale). An equalizing charge is a charge on top of a charge that brings all cells to full-charge saturation. This service must be administered with care because excessive charging can harm the acer travelmate 6592 battery. A difference in specific gravity of 40 points poses a performance problem and the cell is considered defective. A 40-point difference is one cell having an SG of 1.200 and another 1.240. A charge may temporarily cover the deficiency, but the flaw will resurface after a few hours of rest due to high self-discharge.
Applying momentary high-current bursts to repair a shorted NiCd or NiMH cell has been tried but offers limited success. The short may temporarily evaporate but the damage in the separator remains. After service, the repaired cell may charge normally and reach correct voltages; however, high self-discharge will likely drain the battery and the short will return.
It is not advised to replace a shorted cell in an aging pack because of cell matching. The new cell will always be stronger than the others. Consider the biblical verses: “No one sews a patch of unshrunk cloth on an old garment. If he does, the new piece will pull away from the old, making the tear worse. And no one pours new wine into old wineskins. If he does, the wine will burst the skins, and both the wine and the wineskins will be ruined” (Mark 2:21, 22 NIV). Replacing faulty cells often leads to battery failures within six months. It’s best not to disturb the cells. Instead, allow them to age naturally as an intact family.
Shorts or high leakage in a Li-ion cell are uncommon. If this occurs, the cell becomes unstable and a massive amount of power can dissipate, leading to a possible venting thermal breakdown. Such a leak can be compared to drilling a small pinhole into a high-pressure gas pipeline and holding a match to it. The resulting explosion could rupture the pipe. Similarly, the rushing current in the cell heats up the tiny malfunction, causes a major leak and releases all energy within seconds. (Read more about Safety circuits for modern batteries)
Cell disintegration caused by internal disturbances lies outside the safeguarding ability of the protection circuit. Most cell failures occur when the asus a32-f5 battery has been damaged by shock and vibration, has been overcharged or has been overheated. Li-ion cells for electric powertrains and demanding industrial applications use a heavy-duty separator to reduce the risk of an electrical short. These batteries are larger than consumer-type packs. Saying that Li-ion has twice the energy density of NiCd can be a misnomer; some long-lasting Li-ion cells have a specific energy as low as 60Wh/kg, the same as NiCd.
Loss of Electrolyte
The loss of electrolyte in a flooded lead acid battery occurs through gassing, as hydrogen escapes during charging and discharging. Venting causes the electrolyte to become more concentrated and the balance must be restored by adding clean water. Do not add electrolyte, as this would upset the specific gravity and shorten battery life through excessive corrosion.
Permeation, or loss of electrolyte in sealed lead acid batteries, is a recurring problem that is often caused by overcharging. Careful adjustment of charging and float voltages, as well as operating at moderate temperatures, reduces this failure. Replenishing lost liquid in VRLA batteries by adding water has limited success. Although the lost capacity can often be regained with a catalyst, tampering with the cells turns the stack into a high-maintenance project that needs constant supervision.
Nickel-based batteries can lose electrolyte through venting due to excessive pressure during extreme charge or discharge. After repeated venting, the spring-loaded seal of the cells may not seal properly again, and the deposit of white powder around the seal opening is evidence of this. Losses of electrolyte may also occur as part of faulty manufacturing. Dry-up conditions result in a “soft” cell, a defect that cannot be corrected. On charge, the voltage of a “dry” cell goes high because the battery has no clamping action and does not draw current.
A properly designed and correctly charged lithium-ion cell should not generate gases, nor should it lose electrolyte through venting. In spite of what advocates have said, lithium-based cells can build up an internal pressure under certain conditions, and a bloated pouch cell is proof of this. Read more about The Pouch Cell. Some cells include an electrical switch that opens if the cell pressure reaches a critical level. Others feature a membrane that releases gases. Many of these safety features are one-way only, meaning that once activated, the cell becomes inoperable. This is done for safety reasons.
Permanent battery defects include high internal resistance, elevated self-discharge, electrical short and capacity fade. Poorly designed chargers, exposure to excess heat, harsh charge and discharge cycles, and inappropriate storage contribute to early aging. Let’s examine the cause of these non-correctable battery problems and explore what we can do to minimize them.
Low-capacity Cells
A manufacturer cannot predict the exact capacity when a battery comes off the production line, and this is especially true with lead acid batteries that involve manual assembly. Fully automated cell production in “clean rooms” also causes performance differences, and as part of quality control, each cell is measured and segregated into categories according to their inherent capacity levels. The high-capacity A-cells are reserved for special applications and sold at premium prices; the large mid-range B-group goes to commercial and industrial markets; and the low-grade C-cells may end up as consumer products in department stores. Cycling will not significantly improve the capacity of the low-end cell, and even though the cell may look good, the buyer must be aware of differences in capacity and quality, which often translate into life expectancy.Cell Mismatch, Balancing
Matching of cells according to capacity is important, especially for industrial batteries. No perfect match is possible, and if slightly off, nickel-based cells adapt to each other after a few charge/discharge cycles similar to the players on a winning sports team. High-quality cells continue to perform longer than the lower-quality counterpart, and the cells degrade at a more even and controlled rate. Lower-grade cells, on the other hand, diverge more quickly with use and time, and failures due to cell mismatch are more widespread. Cell mismatch is a common cause of failure in industrial batteries. Manufacturers of professional power tools and medical equipment are careful in the choice of cells to attain good battery reliability and long life.Let’s look at what a weak cell does in a pack that is strung together with strong ones. The weak cell holds less capacity and is discharged more quickly than the strong brothers. Going empty first, the strong brothers overrun this feeble sibling and the resulting current on a continued discharge pushes the weak cell into reverse polarity. Nickel-cadmium can tolerate a reverse voltage of minus 0.2V and a reverse current of a few milliamps, but exceeding this level will cause a permanent electrical short. On charge, the weak cell reaches full charge first and it goes into heat-generating over-charge while the strong brothers still accept charge and stay cool. The low cell experiences a disadvantage on both charge and discharge. It continues to weaken until finally giving up the struggle.
The capacity tolerance between cells in an industrial battery should be +/– 2.5 percent. High-voltage packs designed for heavy loads and wide adverse temperature ranges should have lower tolerances. There is a strong correlation between cell balance and longevity.
Li-ion cells share similar deficiencies with nickel-based systems and need management. The mandatory protection circuit supervises the serially connected cells by clamping the voltage when exceeding 4.25 and 4.35V on charge, and disconnecting the pack from discharge when the weakest cell drops to between 2.50 and 2.80V/cell. This prevents the stronger cells from pushing the depleted cell into reverse polarization. The protection circuit acts like a guardian angel that shields the weaker siblings from being bullied by the stronger brothers. This may be help to explain why Li-ion packs for power tools last longer than nickel-based batteries, which normally do not have a protection circuit.
The capacity of quality Li-ion cells is consistent and the self-discharge is low. A problem arises when the cells exhibit a discrepancy in self-discharge. This can be attributed to lower-quality cells or high-temperature spots in a large automotive battery, which hastens aging. Balancing is required and there are two methods: Passive balancing bleeds the high-voltage cells; active balancing shuttles the extra charge from higher-voltage cells to the lower-voltage cells without burning the energy. Active balancing is the preferred method on EVs.
With use and time all batteries become mismatched, and this also applies to lead acid. Shorted cells and those having high self-discharge are a common cause of cell imbalance and lead to subsequent failure. Manufacturers of golf cars, aerial work platforms, floor scrubbers and other battery-powered vehicles recommend an equalizing charge of 3–4 hours if the voltage difference between the cells is greater than +/– 0.10V, or if the specific gravity varies more than 10 points (0.010 on the SG scale). An equalizing charge is a charge on top of a charge that brings all cells to full-charge saturation. This service must be administered with care because excessive charging can harm the acer travelmate 6592 battery. A difference in specific gravity of 40 points poses a performance problem and the cell is considered defective. A 40-point difference is one cell having an SG of 1.200 and another 1.240. A charge may temporarily cover the deficiency, but the flaw will resurface after a few hours of rest due to high self-discharge.
Shorted Cells
Manufacturers are at a loss to explain why some cells develop high electrical leakage or a short while still new. The culprit might be foreign particles that contaminate the cells during manufacture, or rough spots on the plates that damage the delicate separator. Clean rooms, improved quality control at the raw material level, and minimal human handling during the manufacturing process have reduced the “infant mortality rate.”Applying momentary high-current bursts to repair a shorted NiCd or NiMH cell has been tried but offers limited success. The short may temporarily evaporate but the damage in the separator remains. After service, the repaired cell may charge normally and reach correct voltages; however, high self-discharge will likely drain the battery and the short will return.
It is not advised to replace a shorted cell in an aging pack because of cell matching. The new cell will always be stronger than the others. Consider the biblical verses: “No one sews a patch of unshrunk cloth on an old garment. If he does, the new piece will pull away from the old, making the tear worse. And no one pours new wine into old wineskins. If he does, the wine will burst the skins, and both the wine and the wineskins will be ruined” (Mark 2:21, 22 NIV). Replacing faulty cells often leads to battery failures within six months. It’s best not to disturb the cells. Instead, allow them to age naturally as an intact family.
Shorts or high leakage in a Li-ion cell are uncommon. If this occurs, the cell becomes unstable and a massive amount of power can dissipate, leading to a possible venting thermal breakdown. Such a leak can be compared to drilling a small pinhole into a high-pressure gas pipeline and holding a match to it. The resulting explosion could rupture the pipe. Similarly, the rushing current in the cell heats up the tiny malfunction, causes a major leak and releases all energy within seconds. (Read more about Safety circuits for modern batteries)
Cell disintegration caused by internal disturbances lies outside the safeguarding ability of the protection circuit. Most cell failures occur when the asus a32-f5 battery has been damaged by shock and vibration, has been overcharged or has been overheated. Li-ion cells for electric powertrains and demanding industrial applications use a heavy-duty separator to reduce the risk of an electrical short. These batteries are larger than consumer-type packs. Saying that Li-ion has twice the energy density of NiCd can be a misnomer; some long-lasting Li-ion cells have a specific energy as low as 60Wh/kg, the same as NiCd.
| Caution: | Applying a high current burst works best with nickel-based batteries. Do not use this method for lithium-ion cells. |
Loss of Electrolyte
The loss of electrolyte in a flooded lead acid battery occurs through gassing, as hydrogen escapes during charging and discharging. Venting causes the electrolyte to become more concentrated and the balance must be restored by adding clean water. Do not add electrolyte, as this would upset the specific gravity and shorten battery life through excessive corrosion.
Permeation, or loss of electrolyte in sealed lead acid batteries, is a recurring problem that is often caused by overcharging. Careful adjustment of charging and float voltages, as well as operating at moderate temperatures, reduces this failure. Replenishing lost liquid in VRLA batteries by adding water has limited success. Although the lost capacity can often be regained with a catalyst, tampering with the cells turns the stack into a high-maintenance project that needs constant supervision.
Nickel-based batteries can lose electrolyte through venting due to excessive pressure during extreme charge or discharge. After repeated venting, the spring-loaded seal of the cells may not seal properly again, and the deposit of white powder around the seal opening is evidence of this. Losses of electrolyte may also occur as part of faulty manufacturing. Dry-up conditions result in a “soft” cell, a defect that cannot be corrected. On charge, the voltage of a “dry” cell goes high because the battery has no clamping action and does not draw current.
A properly designed and correctly charged lithium-ion cell should not generate gases, nor should it lose electrolyte through venting. In spite of what advocates have said, lithium-based cells can build up an internal pressure under certain conditions, and a bloated pouch cell is proof of this. Read more about The Pouch Cell. Some cells include an electrical switch that opens if the cell pressure reaches a critical level. Others feature a membrane that releases gases. Many of these safety features are one-way only, meaning that once activated, the cell becomes inoperable. This is done for safety reasons.
2011年3月1日星期二
Seesaw Concept Offers Easy Tips On Getting Batteries Out
Getting AA batteries out of common household devices can be a real pain in the AAss. Now, with the Seesaw battey concept from Young Suk Kin, the scales may have tipped in your favor.
Sure, AA batteries are great and we couldn’t really do without them. TV remotes, hair trimmers, kids’ toys – any number of devices use these batteries and there is an almost-constant need to change one set or another in a home. While the industry has made strides in creating longer-lasting and rechargeable batteries, they have not addressed the fact that the standard cylinder shape of the things makes them a massive pain to remove once they have become lodged in a favorite toy or necessary remote. Often, it seems as though the slightest imperfection in a device’s battery cavity means that the AA will go in easily but getting it out will require so much force that buying a new – whatever – might just be easier.
No more, says Young Suk Kin and the Seeway battery. No more!
Kin has taken the traditional AA battery design and narrowed the ends, keeping the positive/negative essentials but making the removal process far easier. The tapered ends mean that only small amount of force is needed to pop the Seesaw up and out of the device and into the waiting hand of a user for replacement or charge. Little else about the battery design has changed, aside from coloring and a slightly more sleek middle body – but the ends are a revelation.
While we can see their being problems with shifting batteries or ends that don’t connect quite right, a few iterations of the Seesaw design should be enough to see it working perfectly. It’s clever and simple – something that most great inventions share, and we hope it can get a positive response in the battery market.
Sure, AA batteries are great and we couldn’t really do without them. TV remotes, hair trimmers, kids’ toys – any number of devices use these batteries and there is an almost-constant need to change one set or another in a home. While the industry has made strides in creating longer-lasting and rechargeable batteries, they have not addressed the fact that the standard cylinder shape of the things makes them a massive pain to remove once they have become lodged in a favorite toy or necessary remote. Often, it seems as though the slightest imperfection in a device’s battery cavity means that the AA will go in easily but getting it out will require so much force that buying a new – whatever – might just be easier.
No more, says Young Suk Kin and the Seeway battery. No more!
Kin has taken the traditional AA battery design and narrowed the ends, keeping the positive/negative essentials but making the removal process far easier. The tapered ends mean that only small amount of force is needed to pop the Seesaw up and out of the device and into the waiting hand of a user for replacement or charge. Little else about the battery design has changed, aside from coloring and a slightly more sleek middle body – but the ends are a revelation.
While we can see their being problems with shifting batteries or ends that don’t connect quite right, a few iterations of the Seesaw design should be enough to see it working perfectly. It’s clever and simple – something that most great inventions share, and we hope it can get a positive response in the battery market.
2011年2月15日星期二
Mod Your Nexus S With This DIY Battery Cover
With Google’s latest smartphone, the Nexus S, being less than a few weeks old, we’re guessing you haven’t had time to rack up a ton complaints. The phone does sport a Super AMOLED screen, 5 megapixel camera, Google’s latest mobile operating system (Android 2.3) and even a 1 GHz Hummingbird processor. What more could you want?
But maybe your problem isn’t with the internals of the highly sought after Nexus S. What if the phone’s texture or aesthetics just aren’t to your complete liking? Well, surprisingly, you’re not alone.
As many smartphone lovers get their hands on the Nexus S, one complaint has surfaced on the net. Some feel the glossy back battery cover of the Nexus S collects too many fingerprints and feels downright cheap. For a phone that costs over $500 out of contract, we can’t exactly blame those who feel certain aspects seem cheap. But, aside from purchasing a case, what are your options? One crafty DIYer has come up with the perfect solution.
This Nexus S user, used a product called Plasti Dip to stabilize and reinforce the phone’s battery cover. Plasti Dip is a DIY rubberized coating that allows users to protect all kinds of objects in their home. While the product is usually applied to items like tools, the coating also makes for a nice DIY battery cover. And, not only does this coating strengthen the back, but it also removes the cover’s ability to obtain fingerprints.
Want to get in on this DIY action? Surprisingly, it’s very simple. First start by placing duct tape over the phone’s camera and flash glass. This ensures that you don’t accidentally interfere with your ability to take photos. Next simply place the Plasti Dip inside out on the smart phone battery cover. Make sure you coat the entire back. Failing to do so could cause the product to peal. You’ll want to apply more than one coat, though the exact number is pretty much up to you. Go for something that feels both solid and comfortable. Remember, you’re most likely under a two year contract. You’ll want to make sure the cover is as comfortable as it can possibly be.
But maybe your problem isn’t with the internals of the highly sought after Nexus S. What if the phone’s texture or aesthetics just aren’t to your complete liking? Well, surprisingly, you’re not alone.
As many smartphone lovers get their hands on the Nexus S, one complaint has surfaced on the net. Some feel the glossy back battery cover of the Nexus S collects too many fingerprints and feels downright cheap. For a phone that costs over $500 out of contract, we can’t exactly blame those who feel certain aspects seem cheap. But, aside from purchasing a case, what are your options? One crafty DIYer has come up with the perfect solution.
This Nexus S user, used a product called Plasti Dip to stabilize and reinforce the phone’s battery cover. Plasti Dip is a DIY rubberized coating that allows users to protect all kinds of objects in their home. While the product is usually applied to items like tools, the coating also makes for a nice DIY battery cover. And, not only does this coating strengthen the back, but it also removes the cover’s ability to obtain fingerprints.
Want to get in on this DIY action? Surprisingly, it’s very simple. First start by placing duct tape over the phone’s camera and flash glass. This ensures that you don’t accidentally interfere with your ability to take photos. Next simply place the Plasti Dip inside out on the smart phone battery cover. Make sure you coat the entire back. Failing to do so could cause the product to peal. You’ll want to apply more than one coat, though the exact number is pretty much up to you. Go for something that feels both solid and comfortable. Remember, you’re most likely under a two year contract. You’ll want to make sure the cover is as comfortable as it can possibly be.
2011年1月23日星期日
CMOS Battery
The CMOS battery is a small battery that powers certain components on a computer's motherboard while the computer is turned off. The battery is a 3 volt lithium button cell and has a lifespan of up to ten years. Without a CMOS battery, many important computer systems would not be able to function.
Identification
CMOS batteries are usually CR2032 batteries. They are small, silver circles that sit on the computer's motherboard.
Function
The CMOS toshiba pa3534u-1bas laptop battery maintains the system clock and the memory that stores the BIOS while the computer is powered off.
Effects
A CMOS battery offers warning signs before it dies. The most common problem is a system time that changes each time the computer starts.
Expert Insight
If a computer has been left off for an extremely long period of time and will not boot, the CMOS battery may need to be replaced.
Fun Fact
Even though the CMOS toshiba pabas076 battery is integral to the function of the computer, it is the easiest and most inexpensive component to replace.
Identification
CMOS batteries are usually CR2032 batteries. They are small, silver circles that sit on the computer's motherboard.
Function
The CMOS toshiba pa3534u-1bas laptop battery maintains the system clock and the memory that stores the BIOS while the computer is powered off.
Effects
A CMOS battery offers warning signs before it dies. The most common problem is a system time that changes each time the computer starts.
Expert Insight
If a computer has been left off for an extremely long period of time and will not boot, the CMOS battery may need to be replaced.
Fun Fact
Even though the CMOS toshiba pabas076 battery is integral to the function of the computer, it is the easiest and most inexpensive component to replace.
2011年1月4日星期二
Intel's Mobile Sandy Bridge Tested
Intel has been, in a word, dependable in terms of promising and delivering new mobile chips at the Consumer Electronic Show (CES) for the last couple of years. But every year has only brought a variation of the same theme: Processor (CPU) performance gets a huge lift, either from the addition of physical cores or some nifty-sounding Intel technology (i.e Hyper-Threading, Turbo Boost). Battery performance is barely impacted, for better or worse, while tradition dictates that integrated graphics performance is usually the butt of all jokes.Not this year, though. Intel's new processors (codenamed "Sandy Bridge") are the next generation of Core processors, ushering in a new era where the focus isn't solely on the CPU. This time, the graphics component has been moved onto the same die as the CPU. By placing them that much closer to each other, not only do graphics and CPU performance hit unprecedented highs, but their margins of increase are very compelling. And battery efficiency remains dominant to other solutions out there, despite the major increase in horsepower. So how significant is CPU performance? Can all of your latest 3D gaming titles run on this new integrated graphics chipset? We put Intel's Sandy Bridge through its paces.
How We Tested
We received a 17-inch "whitebook" from Intel, an early test laptop devoid of any kind of branding. Internally, however, this laptop is production-ready, loaded with some of the newest, fastest mobile parts known to man. Our test laptop runs on a 2.3-GHz Intel Core i7-2820QM CPU, which is based on the new Sandy Bridge platform. It's a quad-core processor, joined by 4GB of DDR3 memory and the Intel HD Graphics 3000, otherwise known as the on-die integrated graphics chip. Remember, the previous-generation quad-core processors didn't have integrated graphics, so they were always paired with some discrete graphics chip from either Nvidia or ATI. Every Intel quad-core CPU-equipped laptop going forward will have the option of running on just integrated graphics. Rounding out the rest of the laptop is a 128GB Intel SSD, a Blu-ray drive, and an eight-cell 71WH hp compaq business notebook nx5000 battery.
For comparison purposes, we gathered a nice mix of laptops from this past year. In one corner, there's the Dell XPS 17, which runs on a 1.7-GHz Intel Core i7-740QM, 6GB of DDR3 memory, and an Nvidia GeForce GT 445M discrete graphics chip. We also grabbed a Samsung RF710-S02US, a 17-inch laptop equipped with a Core i7-720QM (1.6GHz), 4GB of DDR3 memory, and the Nvidia GeForce GT 330M. We needed a laptop that ran on integrated graphics only, in order to better gauge just how far the new Intel HD Graphics 3000 series has come in terms of 3D gaming performance. For this task, we grabbed the Dell Inspiron 17R-2950MRB, which runs on a 2.53-GHz dual-core Intel Core i5-460M, 4GB of DDR3 memory, and the Intel GMA HD (on the Core i5).
Huge Performance GainsJust to give you an idea of how powerful Sandy Bridge is, no laptop, even the most powerful one, has ever scored over 10,000 points in PCMark Vantage—a benchmark test that stresses all the major components of a laptop (CPU, memory, graphics, etc). Our Sandy Bridge test unit scored 16,680 points, which is roughly 2.5 times better than the Dell XPS 17 (6,367) and Samsung RF710-S02US (6,000). Its score is so one-sided that several of us had to do a double-take, which is saying a lot.
Transcoding an AVI video file to MPEG-4 using an application like Handbrake is what you call a CPU-intensive test. While the Dell XPS 17 (2 minutes 51 seconds), Samsung RF710 (3:03), and Dell Inspiron 17R (2:52) finished near the 3-minute mark, the Sandy Bridge system finished the same test in 1 minute 47 seconds—a minimum 61-percent increase. New technology also impacts memory performance, as indicated by our Adobe Photoshop CS5 scripts—a memory-intensive test. The Sandy Bridge unit finished our scripts in 3 minutes 19 seconds, while its competitors finished closer to 5 minutes—a minimum 42 percent increase in memory performance, even though the 4GB DDR3 memory capacity is consistent with the other systems in this group. Cinebench R11.5 is a terrific multithreaded benchmark, utilizing all four cores over the course of the test. The highest score on a laptop until now had been the Dell XPS 17's 3.2; the Sandy Bridge unit shattered this record with a score of 5.71—a 78-percent increase.
Replacement for Dell Latitude D630 Laptop Battery
Battery Type: Li-ionBattery Volt: 14.8V
Battery Capacity: 2200mAh
Battery Weight: 351.54g
Battery Color: Metallic Grey
Battery Size: 185.10x66.45x19.10mm
Product Code: NDE048
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Graphics Milestone
Graphics performance has always been Intel's Achilles' heel, as seasoned gamers tend to shop for discrete GPUs (from either Nvidia or ATI) to go with their laptops. With Sandy Bridge, the on-die graphics can easily replace an entry-level to midrange discrete GPU, making graphics one less thing to shop for in a laptop. So how well did the new integrated graphics do, now that it's sitting on the same die as the processor? On our 3DMark06 tests, its 5,731 score is comparable to a midrange discrete graphics chip, like the ATI Mobility Radeon 5470 or the Nvidia GeForce 320M (think Apple MacBook Air 13-inch). It scored about 2.5 times better than the Dell Inspiron 17R (2,023), which is based on the previous-generation integrated graphics—the Intel GMA HD (Core i5). Against the Dell XPS 17 (11,345) and Samsung RF710-S02US (8,004), however, Sandy Bridge's integrated graphics still has a long way to go.
At the medium setting (1,024-by-768 resolution), Sandy Bridge scored respectably in two of the most 3D-intensive games in the world—Crysis (21.2 frames per second) and Lost Planet 2 (22.3 fps). Over 20 fps means that these games are playable, but only at these settings. Cranking up the eye candy and resolution (to 1,600 by 900) almost grinded game play to halt. By comparison, the Dell Inspiron 17R couldn't even run these two games at their lowest settings. We also tried Tom Clancy's H.A.W.X. 2, a jet-fighter combat game with flight-sim elements, which Sandy Bridge handled quite well: The planes, environment, and most of the visuals looked pretty good. The only thing it couldn't take advantage of is a DirectX 11 feature called Terrain Tessellation (Sandy Bridge doesn't support DirectX 11). StarCraft II and World of Warcraft, popular strategy games with moderate levels of 3D intensity, delivered smooth game play at medium settings.
Replacement for TOSHIBA PA3285U-1BAS Laptop Battery
Battery Type: Li-ionBattery Volt: 10.8V
Battery Capacity: 4400mAh
Battery Weight: 433.76g
Battery Color: Black
Battery Size: 129.60x71.76x20.20mm
Product Code: NTB035
Sale price: AU $67.99
Does this mean hard-core gamers shouldn't shop for a discrete GPU and let Sandy Bridge do all the graphics dirty work? Of course not. If you want high frame rates and greater detail, or if you want to compete on a serious level, a discrete GPU is still the way to go. And Sandy Bridge wasn't compatible with all the games that we tried. For instance, Take-Two's Mafia II wouldn't launch at all. For novice and part-time gamers, Sandy Bridge's integrated graphics is a great platform to start on, and it's more battery efficient than running a discrete chipset.
Battery Performance
The good news is that despite cranking up CPU and GPU horsepower, Intel managed to keep thermals in check. In other words, battery life didn't suffer. If this was last year, a quad-core laptop would have had no choice but to pair itself with a battery-guzzling discrete GPU. Quad-core systems like the Dell XPS 17 (3:01) and Samsung RF710-S02US (3:07) barely made it past 3 hours in MobileMark 2007, and much of the blame can be directed at their frame rate–crushing Nvidia GPUs.
The Dell Inspiron 17R-2950MRB, running on just integrated graphics, squeezed 4 hours 9 minutes out of its 47WH battery (6-cell), setting the stage for Sandy Bridge. Our test system, equipped with a 71WH battery (almost a third bigger than that of the 17R), finished the MobileMark 2007 test in 6:24. This sounds about right, as battery performance is still dictated by how big the battery is. Yet, you come to the realization that a quad-core laptop just delivered over 6 hours of battery life. As compelling as the extra graphics power is, it's hard not to be impressed by this kind of toshiba PA3593U-1BAS battery life on such a big and powerful laptop.
Final Word
Keep in mind that this is the quad-core version of Sandy Bridge, meaning Intel likes to launch its meanest and most ferocious processors first. The dual-core versions (Core i3 and i5) aren't likely to see such dramatic gains, but they'll be impressive nonetheless, especially in the graphics area.
Those who will benefit most from Intel's new Sandy Bridge architecture are hard-core content creators, such as professions and hobbies pertaining to video and photography. These tasks will be that much quicker to edit and produce. For media consumption, like watching a Blu-Ray movie, taking in a Hulu or YouTube video, or landing on the most JavaScript-intense Web site, these performance gains won't affect you, as previous generation laptops were doing them with ease. The people that Sandy Bridge will affect the most are aspiring gamers who were intending to spend an extra $50 on a midrange discrete graphics chip, which they can now apply to something else.
Article comes from:http://www.pcmag.com/article2/0,2817,2374911,00.asp
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