Maintenance 5
Agilent U1251A/U1252A User’s and Service Guide 107
Charging the Battery
This meter is powered by a 7.2 V NiMH rechargeable battery.
Use the specified accessory, the 24 V DC adaptor to charge
the battery. Remember never to turn the rotary switch of
the meter when its battery is being charged. Use the follow-
ing procedures to charge the battery:
1 Remove and disconnect the test leads from the meter.
2 Turn the rotary switch to the position. Connect
the power cord to the DC adapter.
3 Plug the Red (+)/ Black (- ) banana terminals of the DC
adapter to the and the “COM” terminals
respectively. The DC adaptor can be replaced with a DC
power supply in order to set the 24 V DC output and the
over current limitation to a value more than 0.5 A.
Ensure that the polarity of the connection is correct.
4 The primary display indicates “bAt” and the ‘SbY” flashes
on the secondary display and a short tone sounds to
remind you whether to charge the battery or not. Press
SHIFT to start charging the battery, or the meter will
automatically start the self- test after the 24 V supply is
applied. We recommend not to charge the battery if its
capacity is over 90%.
Never discharge the battery by shorting it or by reverse polarity in any
subjects. Make sure the battery is the rechargeable type before charging
it. Never rotate the rotary switch when the battery is being charged as DC
at 24 V is being applied to the charging terminals.
For the battery charger, the mains supply voltage should not fluctuate by
plus or minus 10%.
Condition Battery Voltage Proportional Percentage
Trickle (SBY) 6.0 V ~ 8.2 V 0% ~ 100%
Under charging 7.2 V ~ 10.0 V 0% ~ 100%