Million ML1500 Replacement Battery 14.8V 3400mAh LPO155

Million ML1500 / ML1200 — 14.8V Li-ion Replacement Battery (LPO155-14.8V-2.2AH)

This is a 14.8V lithium-ion replacement battery rated at 3400mAh (50.32Wh) for the Million ML1500 and ML1200 portable medical devices. It replaces OEM part numbers LPO155-14.8V-2.2AH and FY-18650LP01555. The cell pack matches the original voltage rail and connector configuration for both models in this line.

• ML1500 and ML1200 compatibility: Both models share the same 14.8V four-cell series configuration, connector pinout, and BMS handshake protocol — that is why one cell pack covers both. Swapping between these two units does not require any firmware or hardware adjustment on the device side.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the bench with BMS communication active. The protection circuit responded correctly to over-voltage, over-current, and low-voltage cutoff thresholds without triggering a fault state on the host device.
• Post-installation self-test cycle: After fitting this battery, allow the ML1500 or ML1200 to complete its full power-on self-test without interruption. The device runs BMS verification at startup — cutting power during this sequence causes a false battery fault flag that will persist until the next clean reboot.

Why the ML1500 alarms low battery immediately after a confirmed full charge

The ML1500 BMS applies a capacity threshold calibrated to the OEM cell chemistry during self-test. A new replacement cell has not yet completed a full charge-discharge learn cycle, so the device reads state-of-charge conservatively and trips the low battery alarm even when the pack is fully charged. This is not a fault in the replacement cell — it is the BMS operating within its designed verification window. Run one complete charge-to-discharge-to-full-charge cycle before relying on the battery indicator for clinical reference. After that cycle, the alarm threshold calibrates correctly to the new cell's actual capacity.

ML1500 will not power on after the replacement battery sat in storage

Lithium-ion cells self-discharge during storage. If the pack voltage has dropped below approximately 10.0V — which can happen after several months on a shelf — the ML1500's BMS will refuse to initiate, as this sits below its recovery threshold. The fix is to place the battery on charge immediately and leave it connected for a full uninterrupted charge cycle. If the charger does not begin the charge cycle within a few minutes, the pack may need a trickle pre-charge — check that your charger supports recovery mode, or use the device's own charging port at 14.8V input.