How to disable power to the battery before servicing ThinkPad Edge models E220s / E420s
The new ThinkPad Edge E220s and E420s contain and integrated battery. If a customer is going to install an upgrade or replacement part, or a servicer is going to work on the system, they should first disable the battery in BIOS. To get to BIOS to do this, follow these steps:
1. Boot the machine and as soon as you see the Thinkpad Logo, press the F1 button.
(The system should boot into the BIOS Setup screen.) 2. In BIOS the setting to disable the battery is under: Config -> Power -> “Disable built in Battery”
3. This will prompt to disconnect AC power if attached.
4. The next prompt will indicate that the system will be powered off if the user wishes to continue.
5. Once this is done, the battery will be disabled.
6. After service / installation has been completed, then attach AC power for a few seconds to re-enable the battery.