About this replacement
GE Fanuc A98L-0031-0011/L — 6V Li-MnO2 Replacement Battery (BR-AGCF2W)
This 6V, 2200mAh lithium manganese dioxide cell replaces the OEM BR-AGCF2W backup battery in Fanuc PLC systems. It fits the A98L-0031-0011/L and A06B-6093-K001 controller platforms. Its job is to hold SRAM program memory and keep the real-time clock running whenever main power is cut.
- A98L-0031-0011/L and A06B-6093-K001 platform fit: Both part numbers reference the same Fanuc controller battery socket, voltage rail, and cell footprint — 47.80 × 34.20 × 17.40mm. The Li-MnO2 chemistry matches the original flat-discharge curve these controllers expect for stable SRAM retention.
- Bench tested on actual hardware: We ran this cell under continuous low-current drain consistent with Fanuc SRAM and RTC loads. The cell held above the 5.6V SRAM retention threshold throughout the test cycle, and the BMS showed no spurious low-voltage cutoff events.
- Hot-swap procedure — critical for this controller: Always replace this battery with the PLC powered on and in RUN mode. Removing the cell while the controller is powered off will cause SRAM to lose all stored program data. A power-off swap means a full program reload from your programming device is required before the machine can run.
PLC battery alarm not clearing after a confirmed good installation
Fanuc controllers do not automatically clear the battery alarm when a new cell is installed. The alarm flag is written to a register in the controller's system software and must be manually reset through the programming terminal or operator panel. On most Fanuc CNC and PLC platforms, navigate to the alarm or diagnostic screen, confirm the new battery voltage reads above 5.8V, then execute the alarm clear sequence in the system parameter menu. If the alarm persists after a confirmed reset, check the connector seating — the cell posts on the BR-AGCF2W footprint are press-fit and can show intermittent contact if not fully seated.
New cell reading lower than 6V on the controller's battery monitor screen
Li-MnO2 cells are shipped in a storage state and typically present between 5.8V and 5.95V on first installation. This is not a fault. The cell voltage rises to its rated 6V within a few hours once the controller's float charge circuit begins conditioning the cell. If the reading stays below 5.6V after 24 hours on a powered controller, that crosses the SRAM retention floor — remove the cell, verify connector contact, and seat a replacement. Normal operating voltage for this platform should stabilise between 5.9V and 6.1V.