Basic Battery Safety
The chemicals in laptop battery cells are very reactive. This property allows them to produce a large amount of energy, but it also makes them dangerous if handled or used improperly.
- Do not drop, puncture, or otherwise abuse the battery. Physical damage to the battery can lead to a fire hazard. If your battery has been damaged, please discontinue use and dispose of the battery at a proper recycling facility.
- Do not short out the contacts or place the battery in a place with loose metal objects that could touch the contacts and short out the battery. An example would be in a carry bag with loose paperclips.
- Do not put the battery in hot environments. Excessive heat can cause damage to the battery that may result in a fire hazard.
- Do not expose to moisture or get the battery wet. This can cause internal shorts that can lead to a fire hazard.
- Do not try to modify, repair, or adapt the battery for use in another applications. Laptop batteries are carefully designed to work with the computer as a part of a complete system that contains redundant safety mechanisms. Any modifications, tampering, or use in other applications can defeat the safety mechanisms and create a safety hazard.
First Use & Return To Service After Storage
A brand new battery and one that has not been used for some time require a few steps to ensure proper operation:
- Charge the battery overnight. The charge level meter on a new battery or one taken out of storage may provide false readings. The battery may charge past 100% or it may report less than 100% after the charge cycle stops. The longer charge cycle ensures that the battery has enough charge time despite the charge level indications.
- Run the battery through 3 full charge-discharge cycles. This allows the chip in the battery to collect enough data to accurately compute the charge level. If the battery meter is off by a large margin, it may take a few more cycles to allow it to adjust.
Maintaining the Battery Meter
As a laptop battery ages, it's capacity will decrease. This means that they battery meter must be adjusted over time to ensure that it's reading reflects the battery's current capacity. All modern laptop batteries are "smart batteries". This means that they contain a custom micro-controller chip to manage the battery. This chip collects data from each charge-discharge cycle to calculate the current charge level.
The accuracy of the battery meter depends upon the chip having enough recent data. If you have not run your battery down in several months, the data stored in the chip will be too old to provide an accurate reading. A brand new battery will not have any data saved from past cycles and may not provide an accurate reading.
The accuracy of the battery meter is important because Windows and other operating systems use this information to decide when to shutdown. If your battery meter is inaccurate it can cause the computer to shutdown unexpectedly or your computer may shutdown even though there is plenty of energy left in the battery.
- If you leave your battery in your computer, run the battery through a full charge-discharge cycle at least once per month.
- If you have a brand new battery or have not used your battery for several months, run the battery through 3 full charge-discharge cycles.
Active Use & Storage
Many people try to conserve their battery by not using it. This strategy does not work because the effects of improper storage will degrade a battery faster than the wear caused by regular use. Most batteries are rated at more than 400 cycles and have a lifespan of 2-4 years. Using a battery once per week for 4 years would only accumulate 208 cycles. In contrast, a battery stored at full charge in a hot computer running 24-7 can be dead in as little as 6 months. It is recommended to use your computer from battery on a regular basis. This will ensure that the system is properly calibrated and working when you need it.
If you use your battery at least once per month:
- Run the battery through a full charge-discharge cycle at least once per month
- Keep the computer and battery in a cool environment. Do not leave in a car or in direct sunlight.
- Recharge the battery promptly after discharged. Do no leave the battery in a discharged state for long periods of time.
If you do not use your battery at least once per month, you should store your battery:
- Charge the battery to 50%, remove it from the computer, and store it in a cool dry location. Storing Li-Ion batteries at full charge and in hot environments (like in a running computer) will cause a battery to degrade quickly.
- Put the battery back in the computer once per month to check the charge level. Charge the battery back to 50% as necessary. The chip & circuitry in the battery will slowly consume the battery power. If a battery is allowed to discharge too far a safety circuit in the charger will prevent the battery from being recharged.
- When you take the battery out of storage, you need to follow the "First Use & Return To Service After Storage" instructions before use. The battery's charge level will be based upon the data collected before the battery was stored and not based upon the current condition of the battery. This can make the charge meter inaccurate.
