IBM N51 Series

6. Remove the rechargeable battery from the computer.
7. Measure the voltage at the battery terminals.
3( )
2(T)
1(+)
If the voltage is not correct, the rechargeable battery
is discharged or defective. If the voltage is correct,
go to the next step.
8. Using a low-power ohm meter, measure the
resistance at the battery terminals between
2 (T) and 3 (−). The resistance must be
4 kilohms to 30 kilohms.
If the resistance is out of range, replace the
rechargeable battery.
Testing the Backup Battery
1. Remove the keyboard and the top cover.
2. Measure the voltage at the connectors of the backup
battery.
1
2
If the voltage is not correct, the backup battery is
discharged by a short circuit or is defective.
Testing the Standby Battery
Note: The charging time required is 48 hours.
1. Remove the keyboard and the top cover.
2. Connect the AC adapter to the computer.
Pin Voltage (V dc)
1 +8.5 to +12.6
3 Ground
Pin Voltage (V dc)
1 +2.8 to +3.2
2 Ground
30 IBM Mobile Systems HMM - Volume 1