About this replacement
Philips Trilogy 202 — 14.8V Li-ion Replacement Battery (1113779)
This 14.8V, 6400mAh Li-ion battery replaces the Philips OEM part 1113779 in the Trilogy 202 portable ventilator. It supports mobile operation for patients who need respiratory support away from mains power — including those managing COPD, sleep apnea, or neuromuscular conditions. Voltage and capacity match OEM specification exactly.
- Trilogy 202 / Respironics 1043572 compatibility: These units share the same 14.8V battery rail, connector pinout, and BMS communication protocol — which is why part numbers 1043572 and 1055806 cross-reference to the same physical cell pack.
- Bench tested on actual hardware: We ran this pack through the Trilogy 202 charge cycle and confirmed the BMS handshake completed, charge IC accepted the cell, and the device exited charge mode without fault codes.
- Power-on self-test after installation: After fitting this battery, let the Trilogy 202 complete its full startup self-test without interruption. The device runs a BMS verification sequence at boot — cutting power mid-cycle triggers a false battery fault that latches until the next clean reboot.
Trilogy 202 low-battery alarm triggering immediately after a confirmed full charge
The Trilogy 202 BMS compares cell chemistry signatures against OEM baseline thresholds during startup. A new replacement cell hasn't completed a full charge-discharge learn cycle, so the BMS can flag it as underperforming even at 100% state of charge. This is a calibration gap, not a faulty battery. Run one complete charge-to-discharge-to-charge cycle before clinical use — after that cycle, the BMS updates its reference baseline and the alarm clears.
Trilogy 202 refusing to power on after the battery pack sat in storage
Li-ion cells self-discharge during storage, and if the pack drops below approximately 10V total (around 2.5V per cell), the BMS trips into deep-discharge lockout to protect the cells. The Trilogy 202 won't boot from a locked-out pack. Connect the battery to the OEM charger and leave it on charge for a minimum of 30 minutes — most chargers apply a low-current recovery pulse below the BMS re-enable threshold. If the charge indicator doesn't advance after 30 minutes, measure pack voltage at the terminals; anything above 10V should recover with continued trickle charge.