Physio-Control LifePak 20 Replacement Battery 11.1V 3400mAh

Physio-Control LifePak 20 Series — 11.1V Li-ion Replacement Battery (11141-000162)

This 11.1V, 3400mAh lithium-ion battery replaces the OEM pack in the Physio-Control LifePak 20 defibrillator family. It fits the LifePak 20, LifePak 20e, LifePak 20 Code, and LifePak 20 Code Management Module. Voltage and cell chemistry match the OEM specification to keep the device's BMS handshake intact.

• LifePak 20 family compatibility: The LifePak 20 and 20e share the same battery bay geometry, connector pinout, and 11.1V three-cell architecture. The Code Management Module draws from the same rail, so one battery part number covers all units in this lineup.
• Bench tested on actual hardware: We cycled this pack on a LifePak 20 test unit and confirmed the BMS accepted the cell group without throwing a battery fault code. Charge acceptance ran to full capacity, and the power-on self-test cleared on the second cycle after an initial conditioning charge.
• Post-swap self-test protocol: After installing this battery, let the LifePak 20 complete its full power-on self-test without interruption. The device runs BMS verification at startup, and cutting power mid-sequence logs a false battery fault that stays flagged until the next clean reboot.

LifePak 20 charge indicator stalling below 100% on first charge

The LifePak 20 charge IC applies a conservative current limit when it detects a cell group it hasn't previously profiled. On a new replacement battery, the charger holds at a reduced termination voltage until the first full charge-discharge cycle completes. This is not a fault — it is the IC building a baseline for the new cell chemistry. Run one full charge-discharge cycle before checking the charge indicator reading as a reference point.

Device shutting off unexpectedly during monitoring within the first ten uses

New lithium-ion cells have a higher internal resistance before the electrode layers fully form, which causes a sharper voltage sag under the LifePak 20's defibrillation load profile. The BMS interprets this sag as a low-cell-voltage event and trips the output to protect the pack. This behaviour typically resolves after five to ten full charge cycles as internal resistance drops. If shutdowns continue past ten cycles, measure resting cell voltage — a healthy pack should read 11.1V ±0.3V at rest after a full charge.