GW Instek GCP-300 Instruction Manual page 11

GCP-300 has in its design a priority external power circuit therefore it is safe
to simultaneously install the battery and the external power supply. During
usage, removing the external power supply will not produce waveform
anomaly or any damage. However when external power is used for an
extended time (more than 1 week), removal of battery is recommended.
This will avoid leakage of battery since the quality of the batteries is
something that is out of our control.
2. Battery Installation:
(1) Remove the probe from the circuit.
(2) Please push and open battery lid slightly from back of probe.
(3) While observing polarity, attach the new alkaline battery to the battery
connector buttons and place the battery in the specified area.
(4) Please close battery lid properly.
Figure 5. GCP-300 Battery Installation
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