About this replacement
Lawmate PV-900 Series — 3.7V Li-ion Replacement Battery (BA-PV900)
This is a 3.7V 1100mAh Li-ion battery for the Lawmate PV-900 covert recorder. It fits the PV-900, PV-900 EVO HD, and PV-900FM. OEM part number BA-PV900 matches the original cell specification and connector.
- PV-900, PV-900 EVO HD, and PV-900FM compatibility: All three models share the same battery bay dimensions, connector pinout, and 3.7V supply rail. The BA-PV900 part number covers the full production run of this recorder series without modification.
- Bench tested on actual hardware: We cycled this cell through the PV-900 charge circuit and confirmed the protection board communicates correctly with the recorder's BMS. The cell reached full charge without triggering overcurrent or overvoltage faults.
- Pre-session charge requirement: Charge the battery fully before any recording session. The PV-900 writes continuously to flash storage, and a mid-session power cut truncates the active file — the partial recording will not play back correctly.
PV-900 cutting out and corrupting the active recording file
The PV-900 holds the current recording in a RAM buffer before flushing it to flash. When the cell voltage drops below the recorder's minimum operating threshold mid-session, the device shuts down before that flush completes. The result is a truncated or unreadable file for that session. Previously saved recordings on the flash storage are not affected — only the in-progress file is at risk. A degraded original battery that reads partially charged is the most common trigger for this failure.
PV-900 won't power on after a new battery is installed
A replacement cell shipped in storage mode can sit below 3.2V — too low for the PV-900 boot sequence to start. The recorder will appear completely dead even with a fresh battery installed. Connect the unit to its charger for at least 15 minutes before attempting to power on. Once the cell climbs above approximately 3.4V, the boot sequence will run normally.