Leica GEB371 TPS 400 Replacement Battery 12V 8200mAh

Leica TPS 400 / 700 / 800 / 1100 Series — 12V Li-ion Replacement Battery (GEB371)

This is a 12V 8200mAh (98.4Wh) Li-ion battery for the Leica TPS 400, 700, 800, and 1100 series total stations. It replaces OEM part numbers GEB371 and 818916. The battery slots into the instrument's rear battery compartment and powers the EDM, servo drive, and display during field measurement sessions.

• TPS series platform compatibility: The TPS 400 through 1100 series all draw from the same 12V battery rail and use the same mechanical housing and contact layout. That shared architecture means one battery SKU covers the full range — same BMS handshake, same charge termination profile.
• Bench tested on actual hardware: We ran this battery through a full charge cycle and connected it to a TPS 400 unit. The BMS handled EDM initialisation current spikes without tripping, and charge termination occurred cleanly at the expected voltage ceiling.
• Field deployment prep — run calibration first: After installing this battery, run a full calibration cycle through the instrument menu before taking measurements. The TPS series maps battery state during calibration. Skipping this step causes the instrument to trigger premature low-battery warnings on the first measurement session.

BMS lockout after the TPS 400 sat unused in a carry case for months

Li-ion cells self-discharge over time. If a pack sits unused long enough, cell voltage can drop below the BMS protection threshold — typically around 2.5V per cell. When that happens, the BMS cuts the output circuit entirely and the instrument shows no sign of life. To recover the pack, place it on the charger for at least 90 minutes even if no charge LED activates initially — the charger applies a low-current trickle that nudges cell voltage back above the BMS recovery threshold, usually around 3.0V per cell, at which point normal charging resumes.

TPS 400 shuts down mid-measurement with no low-battery warning

This is a voltage sag failure, not a capacity failure. When the EDM fires or the servo motor steps, current draw spikes sharply. An aged or partially depleted cell can't sustain that load without its terminal voltage dropping below the instrument's cutoff threshold — even if the display was showing a healthy charge level a moment before. The instrument reads a voltage collapse and shuts down to protect its electronics. Fully charge the battery before field use, and if shutdowns persist after a full charge, the cells have likely aged past the point where they can deliver the required peak current — replacement is the fix.