About this replacement
Medtronic Primedic DEFI-B — 14.4V Ni-MH Replacement Battery (TB01020701)
This is a 14.4V, 2000mAh Ni-MH replacement battery for the Medtronic Primedic DEFI-B portable external defibrillator. It replaces OEM part number TB01020701 and fits the DEFI-B unit used in emergency medical and ambulance settings. Voltage and capacity match the original specification exactly.
- Primedic DEFI-B compatibility: The DEFI-B runs a proprietary BMS that handshakes with the battery pack at startup. This replacement uses the same 14.4V Ni-MH cell configuration and connector pinout, so the BMS recognises the pack and proceeds through its standard power-on sequence without fault codes.
- Bench tested on actual hardware: We cycled this pack on the DEFI-B platform and monitored BMS communication through charge and discharge. The charge IC accepted the cell chemistry without modification, and the pack passed the device's internal self-test on the second full cycle after an initial conditioning run.
- Post-swap startup protocol: After fitting this battery, allow the DEFI-B to complete its full power-on self-test without interrupting the sequence. Medtronic's BMS runs a chemistry verification at boot — cutting power mid-sequence stores a false battery fault in memory that will persist until the next complete reboot cycle.
Why the DEFI-B self-test fails after a battery swap
The DEFI-B's BMS is calibrated to the charge curve of a conditioned OEM cell. A new replacement pack has not yet established its full charge profile, so the BMS may flag a chemistry mismatch on the first one or two cycles. This is not a fault with the battery — it is the BMS applying a conservative threshold it learned from the previous cell. Running one complete charge-discharge cycle lets the BMS recalibrate its learned parameters to the new pack. After that cycle, self-test results return to normal and the device clears any stored fault flags.
Charge indicator stops short of 100% on first charge after installation
On the first charge, the DEFI-B's charge IC applies a reduced termination current to an unrecognised cell — it reads the new pack as potentially over-capacity and backs off early. The result is a charge indicator that plateaus at roughly 85–90% and does not advance. Disconnect the charger, power on the device to draw the pack down to approximately 11V, then perform a full uninterrupted charge cycle. After this conditioning run the charge IC adjusts its termination threshold and the indicator will reach 100%.