Hamilton Raphael Ventilator 12V Replacement Battery 2300mAh

Hamilton Raphael Ventilator (369086) — 12V Sealed Lead Acid Replacement Battery

This is a 12V, 2300mAh (27.6Wh) sealed lead-acid replacement battery for the Hamilton Raphael portable ventilator, model 369086. It provides backup power during patient transport and protects against ventilation interruption during mains power loss. Voltage and capacity match the original battery specification for this unit.

• Raphael 369086 compatibility: The Raphael uses a 12V SLA cell with a specific physical footprint (178.00 x 66.60 x 35.00mm) and connector arrangement tied to the device's internal power management board. Substituting a different voltage or cell type will prevent the BMS from completing its handshake and cause an immediate fault condition.
• Bench tested on actual hardware: We cycled this cell under a load profile matching the Raphael's standby and active ventilation draw. The BMS accepted the cell on the first full charge cycle, and the device passed its internal self-test without generating a fault.
• Post-swap self-test protocol: After installing this battery, allow the Raphael to complete its full power-on self-test sequence without interruption. The device runs a BMS verification check at startup — cutting power mid-sequence causes a false battery fault that will persist until the next clean reboot.

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

The Raphael's BMS uses a charge threshold calibrated to the original factory cell. A new replacement SLA cell has a slightly different internal resistance profile in its first few cycles, which the BMS reads as a capacity shortfall even when the cell is fully charged. This is not a fault with the battery. Run one complete charge-discharge cycle and the BMS will recalibrate its threshold against the new cell's actual behaviour. The alarm will clear once the cell voltage holds above 12.6V through a full discharge-recharge pass.

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

Sealed lead-acid cells self-discharge during storage, typically dropping below 12V after several months. If the cell voltage falls below the Raphael's BMS recovery threshold — approximately 10.5V — the device will not power on and will not begin charging the battery either. Connect the battery to a standalone SLA charger first and bring the cell back above 11V. Once voltage recovers, reinstall and connect to mains power; the Raphael will then accept the cell and resume normal charging.