About this replacement
Braun Perfusor FT / Perfusor VII — 7.2V Ni-MH Replacement Battery (BRA135)
This is a 7.2V, 1500mAh Ni-MH battery that replaces part numbers BRA135, 120009, BATT/110009, and 34502947 in Braun Perfusor FT and Perfusor VII infusion pumps. These portable syringe pumps deliver controlled medication infusion during patient treatment and transport. When the original cell degrades, the pump alarms earlier and earlier until it can no longer sustain a treatment session.
- Perfusor FT and Perfusor VII compatibility: Both pump variants use the same 7.2V cell architecture, connector pinout, and BMS communication protocol. One battery covers the full platform without modification.
- Bench tested on actual hardware: We cycled this cell through the Perfusor FT charge circuit and confirmed the BMS accepted the new cell, completed charge termination cleanly, and cleared the low-battery threshold after one full charge-discharge cycle.
- Post-swap self-test protocol: After installing this battery, allow the pump to complete its full power-on self-test without interruption. Interrupting the startup sequence causes the BMS to log a false battery fault that persists until the next clean reboot — this is not a defective cell.
Low battery alarm triggering immediately after a confirmed full charge
The Perfusor FT's BMS compares the new cell's charge profile against thresholds calibrated to a broken-in OEM cell. A fresh Ni-MH cell has a slightly different internal resistance signature on the first cycle, which can push the BMS into a conservative low-battery state even when the cell is fully charged. This is not a fault with the replacement cell. Run one complete charge-to-discharge cycle and the BMS recalibrates its internal model. After that cycle, the alarm threshold behaves normally.
Pump will not power on after battery sat in storage
Ni-MH cells self-discharge in storage. If the cell voltage drops below the Perfusor's BMS recovery threshold — typically around 5.4V for a 7.2V pack — the pump will not boot, and the charge indicator may show no response. Connect the pump to mains power and leave it on charge for a minimum of 30 minutes before attempting to power on. The charge IC needs time to trickle-charge the depleted cell back above the BMS acceptance threshold before a normal charge cycle can begin.