When a battery stops holding charge, you have two options: replace the battery, or attempt to revive it. Reviving a battery is a lot different from simply recharging it after normal use. While recharging is simply a matter of connecting it to a charger and waiting for the battery to rebuild its charge, reviving a battery is not a sure thing, and often fails. Below are some methods commonly used to revive dead batteries.
This method of battery restoration is used to revive lithium-ion batteries that are no longer accurately communicating their level of charge to the device they power, such as a laptop. To recalibrate a battery, charge it to the maximum level it currently holds and let it rest at that level for two hours. Unplug the battery and allow it to drain until the device powers down. Leave the device off for at least three hours before turning it back on to recharge. This method should improve the accuracy of communication between the battery and its device.
Freezing the Battery
Another method of battery revival used for lithium-ion batteries is freezing. When employed properly, this method can provide a moderate increase in battery life. To utilize freezing for battery life, remove the battery from its device and place it in a sealed plastic bag. Freeze it for around 12 hours, remove it from the freezer and allow it to reach room temperature. Reinsert the battery into the device and allow it to charge completely.
One of the most common causes of a dead lithium-ion battery is over discharging. This can occur even if a discharged battery was simply stored for too long. Some dead lithium-ion batteries will respond to boosting, a method of revival that involves applying a small charge to activate the battery before applying normal charge. However, this method should not be used on batteries with a charge that has fallen below 1.5 V per cell for more than one week.
Reconditioning is a restoration technique that works only on nickel-cadmium batteries. The goal of reconditioning is to remove any crystals that have formed in the battery's cells. Reconditioning involves slowly discharging the battery to a charge of 0.4 volt per cell or lower. If performed properly, reconditioning can eliminate crystals and revive the battery.
Are there any methods for reviving a battery you know about that aren’t listed here? Share them with us! To learn more about the chemistry of batteries, visit our resource center.