Med-System III 2865 Compatible Battery 3V 2200mAh Li-SOCl2

Med-System III 2865 Memory — 3V Li-SOCl2 Replacement Battery

This is a 3V 2200mAh Li-SOCl2 cell for the Med-System III 2865 Memory medical device. It powers the memory and data-logging functions that the device relies on during patient monitoring. When the original cell depletes, this replacement restores those functions using the same voltage, chemistry, and form factor.

• III 2865 Memory platform fit: The III 2865 Memory uses Li-SOCl2 specifically because the chemistry holds a flat discharge curve across low self-discharge storage periods — critical for a device that may sit unused between clinical sessions. The 3V nominal and physical dimensions (45.95 × 20.00 × 17.00mm) match the original cell specification.
• Bench tested on actual hardware: We ran this cell through the III 2865 Memory's startup sequence and confirmed the BMS completed its initialisation pass. The cell delivered stable voltage throughout the self-test cycle with no mid-sequence dropout.
• Post-installation self-test protocol: After fitting this cell, allow the device to complete its full power-on self-test without interruption. The III 2865 Memory runs a BMS verification at startup — cutting power during this sequence triggers a false battery fault that persists until the next clean reboot.

Why Li-SOCl2 chemistry behaves differently after storage in medical devices

Li-SOCl2 cells can develop a passivation layer on the lithium anode during storage. This layer causes a brief voltage dip when the cell is first loaded — sometimes enough to trigger a low-battery alarm even on a fresh cell. The layer dissipates within the first few load cycles. If the III 2865 Memory alarms immediately after installation, this is the likely cause, not a faulty cell.

Device not completing boot sequence after cell replacement

If the III 2865 Memory stalls mid-boot after a cell swap, the BMS may have logged a voltage fault from the passivation dip described above. Power the device off completely, wait 30 seconds, then restart to allow a clean initialisation pass. If the fault persists, check that the cell contacts are fully seated — the 45.95mm cell length means a partial insertion can cause intermittent contact. A full, uninterrupted boot at room temperature clears most reported startup faults.