About this replacement
Primedic Medtronic DEFI-B Series — 14.4V Ni-MH Replacement Battery (TB01020701)
This is a 14.4V, 3000mAh Ni-MH replacement battery for the Medtronic DEFI-B defibrillator and compatible models including the M110, M111, and M112. It replaces OEM part number TB01020701. Capacity figures are taken from product data — 43.2Wh total energy.
- DEFI-B, M110, M111, M112 compatibility: These models share the same 14.4V power rail, TB01020701 connector footprint, and BMS handshake protocol. The cell chemistry is Ni-MH across the entire range, so the BMS charge termination logic — negative delta-V detection — applies identically to all four platforms.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the DEFI-B platform. The BMS completed negative delta-V cutoff correctly at full charge, and the protection circuit responded within spec to load spikes consistent with capacitor recharge draws.
- Post-installation self-test cycle: After fitting this battery, allow the device to complete its full power-on self-test without interruption. The DEFI-B runs a BMS verification sequence at startup — cutting power mid-sequence registers a false battery fault that persists until the next clean reboot cycle.
Why the DEFI-B flags a low-battery alarm on a freshly charged replacement
The DEFI-B BMS was calibrated to the internal resistance profile of a conditioned OEM cell. A new Ni-MH cell has higher internal resistance on the first few cycles, which causes the BMS to read voltage sag under capacitor-recharge load as a depleted state. This is not a fault with the cell. Run one full charge-discharge cycle before clinical use — internal resistance drops significantly after the first full cycle, and the BMS alarm threshold will no longer trip under normal load.
DEFI-B not completing boot sequence after battery sat in storage
Ni-MH cells self-discharge at roughly 1–2% per day under ambient storage. A cell stored for several months can drop below the DEFI-B's BMS minimum recovery threshold — typically around 10.0–10.5V on a 14.4V Ni-MH pack — causing the device to halt mid-boot rather than attempt operation on a borderline supply. Connect the battery to the OEM charger before installing it. Allow a full uninterrupted charge cycle to bring the pack above 13.5V before fitting it in the device.