The reliability and longevity of a battery hinges, to a large extent, on the quality of the charger. Battery chargers are often given low priority, especially for consumer products. In this paper we address the charger as the quintessential provider and guardian of the battery. IBM ThinkPad R32 Battery We look at various charge methods that will increase the performance of nickel-based batteries. Charging lithium and lead-based batteries are described on separate papers.

A battery should always remain cool during charging because high temperatures shorten battery life. Some temperature rise with nickel-based batteries cannot be avoided. The time during which the battery temperature remains elevated should be as short as possible. The temperature rise occurs in the second half of the charge cycle. The battery should cool to room temperature when on trickle charge.IBM 02K6928 Battery, IBM 02K7054 Battery, IBM ThinkPad A20 Battery, IBM ThinkPad A20M Battery, IBM ThinkPad A21M Battery, If the temperature remains above room temperature after a few hours in ready mode, the charger is performing incorrectly. In such as case, remove the battery when ready. The caution applies especially to nickel-metal-hydride because this chemistry cannot absorb overcharge well.

Nickel-based chargers are grouped into three categories:

Slow Charger - Also known as 'overnight charger', the slow charger applies a fixed charge of about 0.1C* (one-tenth of the rated capacity) for as long as the battery is connected. Charge time is 14-16 hours. Slow chargers are found in cord-less phones, portable CD players and other consumer goods.

Quick Charger - Also knows as rapid charger, this charger serves the middle range, both in terms of charging time and price. Charging time is 3-6 hours. The charger switches the battery to trickle charge when ready. Quick-chargers are used for cell phones, laptops and camcorders.

Fast Charger - Designed for nickel-based battery, the fast charger fills a pack in about one hour. IBM ThinkPad A20 Battery Fast charging is preferred because of reduced crystalline formation (memory). Accurate full-charge detection is important. When full, the charger switches to topping and then trickle charge. Fast chargers are used for industrial devices such as two-way radios, medical devices and power tools.

New nickel-based batteries should be trickle-charged for 24 hours prior to use. Trickle charge brings all cells to equal charge level because each cell self-discharges at a different rate. Trickle charge also redistributes the electrolyte to remedy dry spots on the separator brought on by gravitation of the electrolyte during long storage.

* The C-rate is a unit by which charge and discharge currents are scaled.IBM 02K6928 Battery, IBM 02K7054 Battery, IBM ThinkPad A20 Battery, IBM ThinkPad A20M Battery, IBM ThinkPad A21M Battery, A charge current of 1000mAh, or 1C, will charge a 1000mAh battery in slightly more than one hour. A 1C discharge lasts one hour.

Some battery manufacturers do not fully form the cells before shipment. Full performance is reached after the battery has been primed through several charge/discharge cycles, either with a battery analyzer or through normal use. In some cases, 50-100 discharge/charge cycles are needed to obtain full performance. Properly formed cells perform to specification after 5-7 cycles.

Most rechargeable cells are equipped with a safety vent to release excess pressure if over-charged. The safety vent on a nickel-based cell opens between 10-13 Bar (150-200 psi). (The pressure of a car tire is about 2.3 Bar or 35 psi.) With a resealable vent, no damage occurs after venting.IBM ThinkPad A20M Battery Some electrolyte is lost and the seal may leak afterwards. A white powder accumulating at the vent opening indicates venting activities.

Charging nickel-cadmium

The overall charge efficiency of nickel-cadmium is about 90% if fast charged at 1C. On a 0.1C overnight charge, the efficiency drops to 70% and the charge time is 14 hours or longer.

In the initial 70% of charge, the charge acceptance of a healthy nickel-cadmium battery is close to 100%. The battery remains cool because all energy is absorbed. Currents of several times the C-rating can be applied without heat buildup. Ultra-fast chargers use this phenomenon to charge a battery to the 70% level within minutes. Past 70%, the battery gradually loses the ability to accept charge. The pressure and temperature increase. Figure 1 illustrates the relationship of cell voltage, pressure and temperature while nickel-cadmium is being charged.

Figure 1: Charge characteristics of a nickel-cadmium cell.
The cell voltage, pressure and temperature characteristics are similar to nickel-metal-hydride.

Ultra-high capacity nickel-cadmium batteries tend to heat up more than the standard version on fast-charge. This is partly due to increased internal cell resistance. To moderate the temperature buildup and achieve short charge times,IBM 02K6928 Battery, IBM 02K7054 Battery, IBM ThinkPad A20 Battery, IBM ThinkPad A20M Battery, IBM ThinkPad A21M Battery, advanced chargers apply a high current at the beginning and then lower the amount to harmonize with the charge acceptance.

Interspersing discharge pulses between charge pulses improves the charge acceptance of nickel-based batteries.IBM ThinkPad A21M Battery Commonly referred to as burp or reverse load charging, this method promotes high surface area on the electrodes to improve the recombination of gases generated during charge. The results are better performance, reduced memory and longer service life.

Full-charge detection is based on a combination of voltage drop at full charge (negative delta V), rate-of-temperature-increase (dT/dt), absolute temperature and timeout timers. The charger utilizes whatever comes first to terminate the fast-charge.

The reusable alkaline was introduced in 1992 as an alternative to disposable batteries. The battery was promoted as a low-cost power source for consumer goods. Attempts were made to open markets for wireless communications, medical and defense. But the big breakthrough never came. Today, the reusable alkaline occupies only a small market and its use is limited to portable entertainment devices and flashlights. The lack of market appeal is regrettable when considering the environmental benefit of having to discard fewer batteries.Toshiba Satellite 2100 Battery It is said that the manufacturing cost of the reusable alkaline is only marginally higher than the primary cell.

The idea of recharging alkaline batteries is not new. Although not endorsed by manufacturers, ordinary alkaline batteries have been recharged in households for many years. Recharging these batteries is only effective, however, if the cells have been discharged to less than 50% of their total capacity. The number of recharges depends solely on the depth of discharge and is limited to a few cycles at best. With each recharge, the amount of capacity the cell can hold is reduced. There is a cautionary advisory. Charging ordinary alkaline batteries may generate hydrogen gas, which can lead to explosion. It is not prudent to charge ordinary alkaline unsupervised.

The reusable alkaline is designed for repeated recharge. Also here,, there is a loss of charge acceptance with each recharge. Fujitsu FPCBP95 Battery The longevity of the reusable alkaline is a direct function of the depth of discharge; the deeper the discharge, the fewer cycles the battery can endure.

Tests performed by Cadex on 'AA'Fujitsu FPCBP77 Battery, Fujitsu FPCBP68 Battery, Fujitsu FPCBP63 Battery, Fujitsu FPCBP95 Battery reusable alkaline cells showed a high capacity reading on the first discharge. In fact, the energy density was similar to that of nickel-metal-hydride. After the battery was fully discharged and recharged using the manufacturer's charger, the reusable alkaline settled at 60%, a capacity slightly below that of nickel-cadmium. Repeat cycling in the same manner resulted in a fractional capacity loss with each cycle. The discharge current in the tests was adjusted to 200mA (0.2 C-rate, or one fifth of the rated capacity); the end-of-discharge threshold was set to 1V/cell.

An additional limitation of the reusable alkaline system is its high internal resistance, Fujitsu FPCBP77 Battery resulting in a load current capability of only 400mA (lower than 400mA provides better results). Although adequate for portable radios receivers, CD players, tape players and flashlights, 400mA is insufficient to power most mobile phones and video cameras.

The reusable alkaline is inexpensive to buy but the cost per cycle is high when compared to other rechargeable batteries. Whereas nickel-cadmium checks in at $0.04US per cycle based on 1500 cycles, the reusable alkaline costs $0.50 based on 10 full discharge cycles. For many applications, this seemingly high cost is still economical when compared to primary alkaline that provides a one-time use. By only partially discharging the reusable alkaline, an improved cycle life is possible. At 50% depth of discharge, 50 cycles can be expected.

To compare the operating cost between the standard and reusable alkaline, a study was done on flashlight batteries for hospital use. The reusable alkaline achieved measurable cost savings in the low?intensity care unit in which the flashlights were used only occasionally. Fujitsu FPCBP77 Battery, Fujitsu FPCBP68 Battery, Fujitsu FPCBP63 Battery, Fujitsu FPCBP95 Battery he high-intensity care unit, which used the flashlights constantly, did not attain the same result. Deeper discharge and more frequent recharge reduced the service life and offset any cost advantage over the standard alkaline battery.

When considering reusable alkaline, one must realize that the initial energy is slightly lower than that of the standard alkaline. Each subsequent recharge/charge cycle causes the capacity to decrease. Cost savings are realized if the batteries are never fully discharged but have a change to be recharged often.
Advantages

Inexpensive - can be used as a direct replacement for non-rechargeable (primary) cells.

More economical than non-rechargeables - allows several recharges.

Low self-discharge - can be stored as a standby battery for up to 10 years.

Environmentally friendly - no toxic metals used, fewer batteries are discarded.(Fujitsu FPCBP63 Battery)

Maintenance free - no need for cycling; no memory.
Limitations

Limited current handling - suited for light-duty applications like portable home entertainment, flashlights.

Limited cycle life - for best results, recharge before the battery gets too low

The newest addition to the lithium-ion family is the A123 System in which nano-phosphate materials are added in the cathode. It claims to have the highest power density in W/kg of a commercially available lithium-ion battery. The cell can be continuously discharged to 100% depth-of-discharge at 35C and can endure discharge pulses as high as 100C. The phosphate-based system has a nominal voltage of about 3.3V/cell and peak charge voltage is 3.60V. Toshiba Tecra 9000 Battery This is lower than the cobalt-based lithium-ion and the battery will require a designated charger. Valance Technology was the first to commercialize the phosphate-based lithium-ion and their cells are sold under the Saphionâ name.

In Figure 4 we compare the energy density (Wh/kg) of the three lithium-ion chemistries and place them against the traditional lead acid, nickel-cadmium, nickel-metal-hydride. One can see the incremental improvement of Manganese and Phosphate over older technologies.Toshiba Tecra 8100 Battery, Toshiba Tecra 9000 Battery, Toshiba Tecra 9100 Battery, Toshiba Satellite 1900 Battery, Toshiba Satellite A60-662 Battery, Toshiba Satellite A65 Series Battery, Cobalt offers the highest energy density but is thermally less stable and cannot deliver high load currents.

Figure 4: Energy densities of common battery chemistries.

Lithium-cobalt enjoys the highest energy density. Manganese and phosphate systems are terminally more stable and deliver high load currents than cobalt.

Definition of Energy Density and Power Density

Energy Density (Wh/kg) is a measure of how much energy a battery can hold. The higher the energy density, the longer the runtime will be. Lithium-ion with cobalt cathodes offer the highest energy densities. Typical applications are cell phones, laptops and digital cameras.
Power Density (W/kg) indicates how much power a battery can deliver on demand. The focus is on power bursts, such as drilling through heavy steel, rather than runtime. Manganese and phosphate-based lithium-ion, as well as nickel-based chemistries, are among the best performers. Batteries with high power density are used for power tools,Toshiba Tecra 9100 Battery, medical devices and transportation systems.

An analogy between energy and power densities can be made with a water bottle. The size of the bottle is the energy density, while the opening denotes the power density. A large bottle can carry a lot of water, while a large opening can pore it quickly. The large container with a wide mouth is the best combination.

Confusion with voltages

For the last 10 years or so, the nominal voltage of lithium-ion was known to be 3.60V/cell. This was a rather handy figure because it made up for three nickel-based batteries (1.2V/cell) connected in series. Using the higher cell voltages for lithium-ion reflects in better watt/hours readings on paper and poses a marketing advantage, however, the equipment manufacturer will continue assuming the cell to be 3.60V.
The nominal voltage of a lithium-ion battery is calculated by taking a fully charged battery of about 4.20V, fully discharging it to about 3.00V at a rate of 0.5C while measuring the average voltage.

Because of the lower internal resistance, the average voltage of a spinel system will be higher than that of the cobalt-based equivalent. Pure spinel has the lowest internal resistance and the nominal cell voltage is 3.80V. Toshiba Tecra 8100 Battery, Toshiba Tecra 9000 Battery, Toshiba Tecra 9100 Battery, Toshiba Satellite 1900 Battery, Toshiba Satellite A60-662 Battery, Toshiba Satellite A65 Series Battery, The exception again is the phosphate-based lithium-ion. This system deviates the furthest from the conventional lithium-ion system

Prolonged battery life through moderation

Batteries live longer if treated in a gentle manner. High charge voltages,Toshiba Satellite 1900 Battery excessive charge rate and extreme load conditions have a negative effect on battery life. The longevity is often a direct result of the environmental stresses applied. The following guidelines suggest ways to prolong battery life.

-The time at which the battery stays at 4.20/cell should be as short as possible. Prolonged high voltage promotes corrosion, especially at elevated temperatures. Spinel is less sensitive to high voltage.

-3.92V/cell is the best upper voltage threshold for cobalt-based lithium-ion. Charging batteries to this voltage level has been shown to double cycle life. Lithium-ion systems for defense applications make use of the lower voltage threshold. The negative is a much lower capacity.

-The charge current of Li-ion should be moderate (0.5C for cobalt-based lithium-ion). The lower charge current reduces the time in which the cell resides at 4.20V. A 0.5C charge only adds marginally to the charge time over 1C because the topping charge will be shorter. A high current charge tends to push the voltage into voltage limit prematurely.

-Do not discharge lithium-ion too deeply. Instead, charge it frequently. Lithium-ion does not have memory problems like nickel-cadmium batteries. No deep discharges are needed for conditioning.

-Do not charge lithium-ion at or below freezing temperature. Although accepting charge, an irreversible plating of metallic lithium will occur that compromises the safety of the pack.

Not only does a lithium-ion battery live longer with a slower charge rate;Toshiba Tecra 8100 Battery, Toshiba Tecra 9000 Battery, Toshiba Tecra 9100 Battery, Toshiba Satellite 1900 Battery, Toshiba Satellite A60-662 Battery, Toshiba Satellite A65 Series Battery, moderate discharge rates also help. Figure 5 shows the cycle life as a function of charge and discharge rates. Observe the improved laboratory performance on a charge and discharge rate of 1C compared to 2 and 3C.

Figure 5: Longevity of lithium-ion as a function of charge and discharge rates.
A moderate charge and discharge puts less stress on the battery, Toshiba Satellite A65 Series Battery resulting in a longer cycle life.

Battery experts agree that the longevity of lithium-ion is shortened by other factors than charge and discharge rates. Even though incremental improvements can be achieved with careful use, our environment and the services required are not always conducive for optimal battery life. In this respect, the battery behaves much like us humans - we cannot always live a life that caters to achieve maximum life span.

Advantages

Inexpensive and simple to manufacture.

Mature, reliable and well-understood technology - when used correctly, lead-acid is durable and provides dependable service.

The self-discharge is among the lowest of rechargeable battery systems.

Capable of high discharge rates.
Limitations

Low energy density - poor weight-to-energy ratio limits use to stationary and wheeled applications.

Cannot be stored in a discharged condition - the cell voltage should never drop below 2.10V.

Allows only a limited number of full discharge cycles - well suited for standby applications that require only occasional deep discharges.

lead content and electrolyte make the battery environmentally unfriendly.

Transportation restrictions on flooded lead acid - there are environmental concerns regarding spillage.
Thermal runaway can occur if improperly charged.

Recycling Attentions
Don’t throw away used rechargeable batteries and cell phones! Recycle them!

All personnel handling RBRC collection boxes should follow these safety guidelines to ensure safe storage and shipping of used rechargeable batteries and cell phones. Call2Recycle mandates a ONE rechargeable laptop battery, ONE bag rule.HP Omnibook XT1500 Battery, Utilize Call2Recycle-provided collection boxes and bags meeting U.S. DOT requirements to properly insulate individual batteries and cell phones for transport.

RBRC’s Call2Recycle program recycles Nickel Cadmium (Ni-Cd), Nickel Metal Hydride (Ni-MH), Lithium Ion (Li-ion), Nickel Zinc (Ni-Zn), and Small Sealed Lead (Pb)* rechargeable hp 338794-001 battery found in cellular and cordless phones, HP Omnibook XT1500 Battery,HP F2019A Battery,HP OmniBook 6000 Battery,cordless power tools, laptop computers, PDAs, two-way radios, camcorders, remote control toys, and other cordless products.

* weighing less than 11 lbs/5 kg each.

Alkaline, lithium, or other non-rechargeable batteries are not accepted for inspiron battery recycling.

Call2Recycle accepts all cell phone makes and models. Phones must be deactivated prior to depositing into the collection box. Do not accept bag or cordless phones.

Used rechargeable batteries may still contain a residual charge that can short-circuit if terminals come in contact with other battery terminals during storage and shipping.

To prevent short-circuits, RBRC mandates a ONE rechargeable hp Pavilion DV4000 battery,HP F2019A Battery, ONE bag rule. Each rechargeable battery, or cell phone with installed battery, must be placed into a separate plastic bag. If plastic bags are unavailable, cover battery terminals with tape (electrical, duct, or masking).

The shipment of rechargeable batteries that have not been properly packaged to prevent short-circuits is a violation of Federal law. Additionally, failure to comply with these Call2Recycle shipping guidelines may lead to a disruption of recycling services.

Place the rechargeable battery and cell phone collection box in a monitored location. The box should be within easy reach of properly trained personnel.

While rechargeable batteries are normally safe to handle, they contain materials that can vent during use. If a rechargeable battery appears to be dirty or to have a white powdery substance around the terminal, exercise caution when handling.HP Omnibook XT1500 Battery,HP F2019A Battery,HP OmniBook 6000 Battery, Do not touch the dirty area. Wash your hands with soap and water. Put the battery in a plastic bag before placing it in the collection box .

Do not attempt to discharge a rechargeable battery by short-circuiting the terminals.

Do not accept wet batteries. Batteries should be dry before being placed into the collection box.

Do not overfill the collection box. When a collection box is full, seal and ship using the prepaid shipping label acer battery .HP OmniBook 6000 Battery, RBRC will automatically ship replacement boxes as needed. Allow up to 3 weeks for delivery.

Exercise caution when handling a collection box filled with rechargeable camcorder batteries and cell phones. It may cause personal injury if dropped. If a collection box breaks and releases its contents, place the rechargeable batteries and cell phones into a new collection box.

maintenance guide
Battery is the consumables, with a limited life expectancy, most manufacturers warranty for the notebook battery time ranging from three months to a year, dell is to follow industry standards to provide a limited warranty for one year. For batteries, use the correct and proper storage, HP F1739A Battery, can significantly extend the laptop battery life of notebook computers.

First, the battery useing must follow some attention points.

1. When you use laptop with external power, you dont need to take out the battery.

There is a chip to prevent over-charging in the mainboard. When the rechargeable battery power to 100% state of charge, the charge control chips (FET) will stop charging the battery. We do not have to worry about damage to the battery.
Connect the dell Inspiron 6400 battery to avoid loss of BIOS information.
To prevent a sudden loss of power break.
2. To prevent exposure to prevent damp to prevent the erosion of liquid chemicals, batteries to avoid contact with metal objects, such as exposure to short-circuit occurrence.

3. Long-term do not use notebooks, how to store the laptop battery?

We will have a period of time not to use the notebook, the dell Inspiron 6000 battery is fully charged to preserve, or to be released after save electricity?

Put long-term preservation of photoelectric batteries will lose their activity and even lead to the control circuit protection self-locking and can not re-use,HP Omnibook XE Battery, full of power will bring about long-term preservation of the safety problems, the best method is to save electricity use to 40 or so and then stored in cool dry place, about 20 degrees Celsius is the ideal storage temperature. Of course, the best month to come up with to use a battery,HP F1739A Battery,HP Omnibook XE Battery,HP F2024A Battery,HP Omnibook XE3 Battery the battery can ensure a good state of preservation, but also does not allow the loss of electricity damage to the battery completely.

How can I exam the Dell battery power? (For example in cell dell Inspiron 1721 battery)

Remove the battery, press the dell Inspiron E1405 battery power signs, we can see the situation of the five battery status lights. For two bright, representing 40% of the electricity. Electricity on behalf of the entire light is sufficient, if the 135-light, that damage the battery.

Second, how to extend as much as possible the work of laptop battery time?

To reduce the screen brightness. How to adjust the brightness of the use of dell Inspiron E1505 battery ,HP F2024A Battery, boot by F2, into the BIOS to adjust the Brightness of Video. Or fn + down / up key combination to adjust the brightness quickly.
Open the CPU speedstep feature, you can greatly extend the working hours of dell Latitude D430 battery; Cpu’s speedstep feature is enabled by default BIOS of. When using batteries, cpu will automatically down-use, in order to achieve energy-saving purpose. If not enabled, please start by F2, into the BIOS found in Performance, for the Speedstep Enable setting Enabled. (An earlier version of BIOS is the Alt + P to the sixth page, modify intel speedstep)
make the best use of standby, sleep and other functions. When a longer period of time without a computer, allowing notebook standby or hibernation, both to save power and extend the life of the computer. (Tips: Please confirm the successful installation of graphics drivers, power management options can be set up.)
WINDOWS in the process of power management settings, we generally can be set to “portable / laptop” (Portable / Laptop).
At the same time suggest that you will use the dell Latitude D500 battery when the wait time to close the monitor is set to 5 minutes, so when we do not operate within a certain period of time the notebook, it will direct the state of black screen, so other than the screen saver to run more power.
when using the battery as much as possible the closure of wireless, HP F1739A Battery,HP Omnibook XE Battery,HP F2024A Battery,HP Omnibook XE3 BatteryBluetooth and infrared ports. At the same time to remove without the use of peripherals and to avoid the opening of a large 3D program, games and so on, in order to reduce unnecessary battery consumption.
Of course, on the controversy over the use of batteries, there are divergent views have any objection if we can HP Omnibook XE3 Battery,.cn forum to ask questions, let us discuss how to maintain the battery.