IVAC Corp Mini Med III B11008 Replacement Battery 3V 2200mAh

IVAC Corp Mini Med III — 3V Li-SOCl2 Replacement Battery (B11008)

This is a 3V lithium-thionyl chloride cell rated at 2200mAh (6.6Wh), replacing OEM part B11008 in the IVAC Corp Mini Med III infusion pump. The Mini Med III is a portable IV medication delivery device used in hospital and home care settings. Fit this cell when the original depletes and the pump can no longer sustain normal operation.

• Mini Med III platform fit: The Mini Med III runs on a single Li-SOCl2 primary cell at 3V. This chemistry provides the flat discharge curve the pump's BMS expects across its full operating load. Swapping to a different chemistry or voltage will trigger immediate fault conditions — the B11008 spec is the only one the pump accepts.
• Bench tested on actual hardware: We ran the B11008 replacement through the Mini Med III startup sequence and confirmed BMS handshake, self-test completion, and steady voltage delivery under the pump's normal delivery load. The cell held within expected voltage tolerance throughout the test cycle.
• Post-installation self-test protocol: After fitting this cell, allow the Mini Med III to complete its full power-on self-test without interrupting the sequence. The BMS runs a battery verification check at startup — cutting power during this window registers a false battery fault that persists until the next clean reboot.

Why the Mini Med III rejects a new B11008 cell on first boot

Li-SOCl2 cells have a known surface passivation layer that forms during storage. On first load, internal resistance reads briefly elevated — enough to push the Mini Med III's BMS voltage threshold check into a fault condition. This is not a defective cell. The passivation layer dissipates within the first operational cycle as the cell comes under load. If the pump refuses the new cell at first boot, power it off, wait 30 seconds, and restart to let the BMS re-evaluate with the passivation effect reducing.

Low battery alarm fires immediately after confirmed B11008 install

The Mini Med III's battery threshold is calibrated to OEM cell impedance values. A freshly installed B11008 that has been in storage shows higher initial impedance due to passivation, and the BMS interprets this as a depleted cell. Run one complete operational cycle — power on, allow the pump to run through a normal delivery load, then power down cleanly. After that first cycle, impedance drops into the expected range and the alarm condition clears. If the alarm persists after the first cycle, measure the open-circuit voltage: a healthy Li-SOCl2 cell should read at or above 3.5V at rest.