About this replacement
Braun Perfusor FT91 / Perfusor F Series — 7.2V Ni-MH Replacement Battery (BRA142)
This is a 7.2V, 3000mAh Ni-MH battery for the Braun Perfusor FT91 and related Perfusor syringe pumps. It replaces OEM part numbers BRA142, 120010, 110010, and BATT/110010. The Perfusor series uses this battery to maintain controlled medication delivery when the pump is operating off mains power.
- Perfusor F, FT91, and secura P compatibility: These models share the same 7.2V battery bay, connector pinout, and BMS handshake protocol. A single cell format — 86.50 × 53.80 × 38.60mm — fits all three without adapter or modification.
- Bench tested on actual hardware: We cycled this cell through the Perfusor's charge and discharge profile. The BMS accepted the cell without fault codes, completed voltage verification, and held steady under the pump's continuous-draw load cycle.
- Post-swap self-test protocol: After installing this battery, allow the Perfusor to complete its full power-on self-test without interruption. The device runs a BMS verification sequence at startup. Cutting power during this window causes a false battery fault that persists until the next clean reboot.
Why the Perfusor FT91 raises a battery fault after a confirmed full charge
The Perfusor's BMS stores a charge acceptance profile from the previous cell. A new Ni-MH cell has a slightly different internal resistance signature, so the BMS may flag a mismatch on the first cycle. This is not a defective battery — it is the controller comparing the new cell against the old cell's learned data. One complete charge-discharge cycle allows the BMS to rewrite that profile to match the new cell. After that cycle, the fault clears and does not return.
Perfusor not completing boot sequence after battery sat in storage
Ni-MH cells self-discharge during storage. If the cell voltage drops below the Perfusor's BMS recovery threshold — typically around 5.4V for a 7.2V pack — the controller will not initiate a boot sequence and the screen stays blank. Connect the pump to mains power first and leave it on charge for a minimum of two hours before attempting to power on from battery alone. Once the BMS detects sufficient cell voltage, the boot sequence proceeds normally. Do not attempt to run the device on battery until the charge indicator has advanced past the first segment.