Mindray A5 Patient Monitor Replacement Battery 11.1V 5200mAh

Mindray A5 / Accutorr Series — 11.1V Li-ion Replacement Battery (022-000008-00)

This 11.1V 5200mAh Li-ion battery replaces the internal pack in the Mindray A5 patient monitor and compatible Mindray monitoring platforms. It fits the A5, Accutorr 3, Accutorr 7, Beneheart R12, and more than 24 additional models sharing the same voltage rail and connector. OEM part numbers covered include 022-000008-00, 115-018012-00, 115-065140-00, LI23S002A, M05-010002-6, and MB583-3S3P.

• Multi-model fit — A5 to Beneheart R12: These models share a common 11.1V three-cell architecture, the same physical connector, and a compatible BMS handshake protocol. One pack covers the full range without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on Mindray monitoring hardware. The BMS completed voltage verification, accepted the charge curve without flagging a fault, and held a stable 11.1V nominal output under clinical load simulation.
• Post-swap self-test protocol: After installing this battery, let the monitor complete its full power-on self-test without interruption. Mindray monitors run a BMS verification sequence at startup — cutting power during this step triggers a false battery fault that sticks until the next clean reboot.

Why the A5 alarms low battery immediately after a confirmed full charge

The Mindray A5 BMS was calibrated against OEM cell chemistry during manufacturing. A new replacement cell has a slightly different internal resistance profile on its first few cycles, and the BMS interprets that resistance signature as a partially depleted pack. This is not a fault with the battery — it is the BMS applying a conservative threshold before it has mapped the new cell. Run one full charge-discharge cycle under normal monitoring load and the alarm clears on subsequent startups.

Monitor will not power on after the replacement battery sat in storage

Li-ion cells self-discharge during storage. If this pack sat uninstalled for several months, its resting voltage may have dropped below the Mindray BMS recovery threshold — typically around 9V for a three-cell 11.1V pack. The BMS will refuse to output power at that voltage to protect the cells. Connect the monitor to mains AC power first and leave it on charge for at least two hours before attempting a battery-only boot. This allows the charge IC to trickle-charge the pack back above the 9V recovery floor before the BMS re-enables discharge.