Million ML1500 14.8V Medical Device Compatible Battery 2600mAh

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

This 14.8V Li-ion battery replaces the original pack in the Million ML1500 and ML1200 portable medical devices. It runs at 14.8V nominal with 2600mAh capacity (38.48Wh). It matches OEM part numbers LPO155-14.8V-2.2AH and FY-18650LP01555 and fits the same physical bay and connector as the factory-installed unit.

• ML1500 and ML1200 platform fit: Both models share the same 14.8V four-cell series configuration, connector pinout, and BMS handshake protocol — which is why one pack covers both. The charge management IC communicates via the same SMBus line on each device, so the replacement integrates without firmware conflict.
• Bench tested on actual hardware: We cycled this pack through charge and discharge on the bench with BMS communication monitoring active. The protection circuit tripped correctly at the low-voltage cutoff threshold and released cleanly on reconnection to the charger. Cell balancing across all four cells held within 20mV at top of charge.
• Power-on self-test — do not interrupt: After installing this battery, let the ML1500 or ML1200 complete its full boot and self-test sequence without removing power or pressing reset. Medical device BMS verification runs during this window, and cutting it short writes a battery fault flag that persists until the next clean reboot cycle.

ML1500 not completing boot sequence after battery swap

The ML1500 runs a BMS handshake check during its power-on sequence. A new replacement cell may report a state-of-charge figure the device's charge IC has not yet calibrated against, causing the boot to stall or loop. This is not a faulty battery — it reflects the charge IC applying conservative thresholds on an unconditioned cell. Complete one full charge to 100% followed by a full discharge under normal device operation, then recharge fully. After that first full cycle the BMS learn routine updates its reference values and the boot sequence completes normally.

Device shutting off unexpectedly during monitoring use

During the first ten cycles, new lithium cells have slightly elevated internal resistance, which causes a larger voltage drop under the load profile a monitoring device applies. If that sag crosses the BMS low-voltage cutoff threshold — typically around 12.0V on a 14.8V four-cell pack — the protection circuit shuts the device down to prevent cell damage. This is not capacity failure; it resolves as internal resistance drops with cycling. If unexpected shutdowns continue past ten cycles, check resting voltage with the device off: it should read at or above 14.0V after a full charge.