HP Codemaster 100 User Manual page 53

Battery Operation
When the LOW BATTERY message is displayed on the monitor, replace the
CAUTION
battery pack with a charged battery pack.
From the time the LOW BATTERY message appears until the battery is fully
depleted and the instrument shuts down, there is approximately thirty
minutes of monitoring and five 360 joule charge-shock cycles.
If the battery is defective, there may be significantly less monitoring time or
charge capacity after the LOW BATTERY message appears than if the battery
is merely depleted. Recording during this time will also impact monitoring
time and the number of charge shock cycles remaining.
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