How to Test a Backup Laptop Batteries on an IBM T21

Testing a laptop batteries can give you an estimate to how long the battery will power a laptop. An IMB T21 ThinkPad battery can power the laptop for a limited amount of time without the need for electricity. This will allow the user to swap out the batteries without having to charge the previous battery. If doing this, you may wish to test the battery to determine the estimate amount of time the battery can charge the laptop for. Line up the battery connectors with the connectors in the battery bay, or battery housing unit. Rotate the battery downward until it is flat and firmly in the battery bay. If the battery does not turn on, you will need to troubleshoot the battery and the AC adapter to ensure they are not dead. 5 Allow the laptop to run on battery power. Some programs and activities use more battery power, causing the battery to die faster.