Szosen OIP-900 Replacement Battery 11.1V 3350mAh

Szosen OIP-900 — 11.1V Li-ion Replacement Battery (JHOTA-990-00)

This 11.1V 3350mAh Li-ion battery is a direct replacement for the Szosen OIP-900 pulse oximeter. It fits the OIP-900 portable oxygen saturation monitor used in clinical and home healthcare settings. Voltage and capacity match the original specification: 11.1V, 3350mAh (37.19Wh).

• OIP-900 platform fit: The OIP-900 runs a three-cell series Li-ion pack at 11.1V nominal. This replacement matches that cell configuration, connector pinout, and BMS handshake protocol — the device power management system will recognise the pack and accept charge input without flagging a foreign battery fault.
• Bench tested on actual hardware: We cycled this pack through the OIP-900 charge circuit and monitored BMS communication at each stage. The protection IC responded correctly to charge termination, over-discharge cutoff, and short-circuit detection across all test runs.
• Post-installation self-test protocol: After fitting this battery, allow the OIP-900 to complete its full power-on self-test without interruption. Medical device BMS verification runs at startup — cutting power mid-sequence registers a false battery fault that persists until the next clean reboot.

OIP-900 alarming low battery immediately after a confirmed full charge

The OIP-900 BMS compares cell voltage and internal resistance against stored OEM baseline values. A new replacement cell has slightly higher internal resistance before the first few charge-discharge cycles, which can push it below the device's alarm threshold even at full state of charge. This is not a fault with the battery — it is the BMS applying conservative thresholds calibrated to a conditioned cell. Run one complete charge-discharge cycle and the internal resistance will drop enough for the BMS to clear the alarm. After that cycle, the device should read charge state accurately.

OIP-900 will not power on after the replacement battery sat in storage

Li-ion cells self-discharge during storage. If the pack voltage drops below approximately 9V — the OIP-900 BMS recovery threshold for a three-cell series pack — the protection circuit locks out power delivery to prevent damage from deep discharge. The device will appear completely dead: no boot, no display, no response to the power button. Connect the charger and leave it uninterrupted for at least 30 minutes to allow the charge IC to apply a low-current pre-charge and bring cell voltage back above the BMS unlock threshold of around 9.9V, after which normal charging resumes.