Backup battery troubleshooting

Verify that the backup battery G2200 is empty U lt 1V . Switch the phone on. Measure voltage of the battery when the main battery is connected to the phone and the phone is switched on. Wait a few minutes and monitor that the backup battery voltage rises. Switch off the phone, disconnect the main battery and monitor that the voltage of the backup battery decreases. Normal behaviour of the voltage is described in the figures below If the voltage rises and falls quickly, check the back-up battery...