Ohmeda Pulse Oximeter 3740 Replacement Battery 12V 2300mAh

Ohmeda Pulse Oximeter 3740 / 3760 Series — 12V Sealed Lead Acid Replacement Battery

This is a 12V, 2300mAh (27.6Wh) sealed lead-acid battery for the Ohmeda Pulse Oximeter 3740, 3760, and 3760P. These monitors measure blood oxygen saturation and heart rate at the bedside, and this battery keeps them running away from mains power. It matches the original voltage, capacity, and terminal configuration for each model listed.

• 3740, 3760, and 3760P compatibility: All three models share the same internal battery bay dimensions, 12V power rail, and BMS handshake protocol. One battery fits the full group without modification.
• Bench tested on actual hardware: We ran this cell through charge acceptance and load cycling on the 3760 platform. The BMS accepted the new cell without triggering a fault, and the charge IC reached target voltage within the expected window.
• Post-swap power-on sequence: After installing this battery, let the monitor complete its full power-on self-test without interruption. The 3740 and 3760 series run a BMS verification check at startup — cutting power during this sequence logs a persistent battery fault that will not clear until the device completes a clean reboot cycle.

Why the 3760P self-test returns a battery fault after a confirmed full charge

Sealed lead-acid cells fresh from storage carry a surface charge that reads as full voltage but does not yet meet the BMS load-test threshold. The 3760P applies a brief internal load during self-test to verify actual capacity — a new cell can fail this check on the first one to two cycles. Run one complete charge-discharge cycle before placing the unit in clinical rotation. After that cycle, the cell's internal resistance drops enough to pass the load test consistently.

Monitor will not power on after battery sat unused in storage

Sealed lead-acid batteries self-discharge over time, and if voltage drops below approximately 10.5V the BMS enters a locked low-voltage state and will not accept a standard charge. The charger sees the cell as a fault condition rather than a depleted battery. Connect the battery to a lead-acid charger with a recovery or soft-start mode — this applies a low-current pre-charge to bring voltage back above the BMS recovery threshold, typically around 11V, before switching to normal charge current.