DATEX-OHMEDA AS-3 Anesthesia Replacement Battery 12V 2300mAh

DATEX-OHMEDA AS-3 Anesthesia / ADU Plus — 12V Sealed Lead Acid Replacement Battery

This is a 12V, 2300mAh (27.6Wh) sealed lead acid battery for the DATEX-OHMEDA AS-3 Anesthesia delivery system and ADU Plus. It provides backup power during surgery or patient transport when mains power is interrupted. Voltage and capacity match the original cell slot specifications for both listed platforms.

• AS-3 and ADU Plus platform fit: Both units share the same 12V SLA bay format and draw from the same backup rail during power interruption. The BMS on each platform reads cell voltage at startup to verify the backup source is within operational range before the unit completes its boot sequence.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the bench. The BMS accepted the cell without fault on the second cycle once resting voltage stabilised above the minimum threshold. First-cycle BMS handshake flagged a conservative low-voltage warning that cleared after one complete charge.
• Post-installation self-test protocol: After fitting this battery, let the AS-3 complete its full power-on self-test without interruption. The BMS runs a voltage verification routine at startup. Cutting power during this sequence causes a persistent battery fault flag that will not clear until the next full reboot with the cell at rest voltage.

Why the AS-3 alarms low battery immediately after a confirmed full charge

The AS-3 BMS compares cell voltage against a threshold tuned for a conditioned OEM cell. A new SLA cell fresh from storage has not yet reached its stable resting voltage, even after one full charge. The BMS reads this slightly lower resting voltage as below threshold and triggers the alarm. Run one complete charge-discharge cycle before clinical deployment — resting voltage will stabilise above the alarm threshold, typically above 12.6V.

AS-3 will not power on after the replacement cell sat in storage

Sealed lead acid cells self-discharge during storage, sometimes dropping below the BMS recovery floor — typically around 10.5V for a 12V SLA. When cell voltage falls below this level, the BMS blocks the power-on sequence entirely rather than risk damage to a deeply discharged cell. Connect the unit to mains and leave it on charge for a full 24-hour recovery cycle before attempting to power on. Check cell voltage at the terminals — if it reads above 10.5V after 24 hours, the BMS should allow normal startup.