GIMA BM3 11.1V Medical Device Replacement Battery 2600mAh

GIMA BM3 / BM3 Plus / BM5 — 11.1V Li-ion Replacement Battery

This 11.1V 2600mAh Li-ion battery replaces the original power cell in the GIMA BM3, BM3 Plus, and BM5 patient monitors. It matches the original voltage rail and physical form factor, fitting directly into the battery bay on all three models. Capacity is 2600mAh (28.86Wh) — identical to the OEM specification.

• BM3, BM3 Plus, and BM5 compatibility: These three monitors share the same battery housing, connector pinout, and 11.1V nominal voltage rail. The BMS on each model reads cell chemistry and voltage in the same way, so one cell fits all three without hardware modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the BM3 platform. The device BMS completed its handshake without fault codes. Charge current tapered correctly at the top of the cycle, and the protection circuit tripped at the expected low-voltage cutoff threshold.
• Power-on self-test after installation: After fitting this battery, allow the monitor to complete its full startup self-test sequence without interruption. The BM3 series runs a BMS verification routine at boot — cutting power during this window registers a false battery fault that persists until the next clean reboot cycle.

Device not completing boot sequence on new battery

The BM3 series performs a BMS learn routine during its first few boot cycles with a new cell. If the battery has partially self-discharged during storage, its resting voltage may fall below the threshold the monitor's firmware expects before it releases the boot sequence. The device stalls partway through startup or loops back to the initial screen. Charge the battery fully before the first installation — confirmed full charge is typically indicated when the charger LED transitions from amber to green and the terminal voltage sits at or above 12.4V.

Charge indicator not reaching 100% on first charge

On the first charge cycle, the BM3's charge IC applies a conservative current limit to an uncharacterised new cell — this is normal behaviour, not a fault. The gauge algorithm has not yet profiled the cell's actual capacity, so it reports a lower state of charge than is real. Run one complete charge-to-discharge-to-charge cycle before relying on the percentage readout for clinical use. After that conditioning cycle, the reported charge level aligns accurately with actual cell capacity.