About this replacement
Philips HeartStart XL+ — 14.8V Li-ion Replacement Battery (989803167281)
This 14.8V, 6600mAh (97.68Wh) lithium-ion battery fits the Philips HeartStart XL+ defibrillator and its Moniteur and Defibrillateur variants. It replaces OEM part numbers 989803167281, M6479, M6479-O, SE02211, and SE-02211. Voltage and cell chemistry match the original specification exactly.
- HeartStart XL+ platform fit: All listed model variants — HeartStart XL+, Moniteur, Defibrillateur — share the same 14.8V battery bay, connector pinout, and BMS communication protocol. One battery covers the full platform without modification.
- Bench tested on actual hardware: We ran charge and discharge cycles on this cell against the HeartStart XL+ BMS. The protection circuit responded correctly to charge termination, over-discharge cutoff, and the defibrillator's capacitor charge load without tripping a false fault.
- Post-installation self-test protocol: After fitting this battery, allow the HeartStart XL+ to complete its full power-on self-test without interruption. The device runs BMS verification at startup — breaking the sequence before it finishes generates a persistent battery fault that won't clear until the next complete reboot cycle.
Self-test failure after battery swap on the HeartStart XL+
The HeartStart XL+ runs an automated self-test that includes a BMS learn cycle on first installation of a new cell. If the device has not yet completed one full charge-discharge cycle with the new battery, the BMS threshold calibration is incomplete and the self-test will flag a battery fault. This is not a defective cell — it is the device's charge IC applying a conservative verification limit to an uncalibrated pack. Run one full charge to 100%, allow the device to discharge through normal use or a controlled test, then recharge fully. After that cycle the self-test should pass and the battery status indicator will read correctly.
HeartStart XL+ alarming low battery immediately after a confirmed full charge
A low-battery alarm directly after charging almost always means the BMS has not yet validated the new cell against its internal voltage threshold table. The OEM BMS was calibrated to the original cell's charge curve, and a fresh replacement cell's resting voltage profile sits slightly outside the learned window until one full cycle resets it. Power the device off completely, leave it off for two minutes to let the BMS reset its state registers, then power back on. If the alarm persists after a second full charge cycle, check that resting cell voltage is at or above 16.4V with a multimeter before concluding a fault.