As with all notebooks, a functioning battery is essential for a ThinkPad user. Some ThinkPad users have reported problems with decreased capacity or non-charging batteries.
Decreased Capacity
Most ThinkPads use Li-on (Lithium-ion) batteries which may report reduced capacity due to calibration issues. Calibrate the battery by allowing it to fully discharge and then recharging it back to full capacity. If a sudden loss in battery capacity is experienced the battery may be defective.
Battery Does Not Charge
Troubleshoot a non-charging battery by confirming that the ThinkPad is plugged into a functioning wall outlet; also make sure your adapter is not defective. The ThinkPad will beep when it is receiving power through the adapter. If the adapter is providing power and the battery does not charge check the battery's temperature. ThinkPad batteries will not charge if they are excessively hot. If the battery still does not charge after cooling down it will need to be serviced or replaced.
Recalls
There have been a few battery recalls under which Lenovo will replace a ThinkPad battery at no charge. An automated tool is available to verify eligibility (see Resources).
Warranty
The default ThinkPad battery warranty is one year. Unlike the warranty on a ThinkPad, the warranty on the battery cannot be extended.
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