About this replacement
Kaba FDU G4 / 132-512003 — 4.8V Ni-CD Replacement Battery (132-512003)
This is a 4.8V 1200mAh Ni-CD replacement battery for the Kaba 132-512003 access control and electronic lock system, including FDU G4 units. It slots into the lock housing and powers the electronic entry mechanism. Voltage and capacity match the original cell exactly — 4.8V, 1200mAh (5.76Wh).
- FDU G4 and 132-512003 compatibility: Both units run on the same 4.8V Ni-CD cell with identical connector pinout and BMS charge profile. Swapping chemistry or voltage on these locks trips the onboard protection circuit and prevents the latch motor from actuating.
- Bench tested on actual hardware: We cycled this cell through the lock's charge and discharge sequence. The BMS accepted the cell without error flags, and the latch motor actuated cleanly through multiple lock and unlock cycles.
- Post-install reconnection on FDU G4 units: After fitting a new cell, wait at least 60 seconds before testing access. The FDU G4 runs a mesh network re-join sequence after any power interruption — presenting a credential before that sequence completes will return an access denial even with a valid code.
Why the Kaba FDU G4 shows a low battery alert immediately after a new cell is fitted
Ni-CD cells self-discharge in storage — a new cell sitting on a shelf can drop to 3.8V or lower before it reaches you. The FDU G4 controller reads pack voltage on power-up and throws a low battery flag if it sees anything below approximately 4.2V. The alert is not a fault with the battery itself. Connect the lock to its normal charging source and allow a full charge cycle to complete — the alert clears once pack voltage crosses the threshold.
Kaba 132-512003 lock not reconnecting to the hub after battery replacement
Pulling the battery breaks the device's network session entirely — the hub does not hold the pairing in a suspended state. When power returns, the lock broadcasts a re-join request, but some hubs require a manual prompt to accept it. Open the access control app, navigate to device management, and trigger a re-pair or re-scan. Once the hub acknowledges the lock, test with a valid credential at 4.8V fully charged.