About this replacement
GE Fanuc D100 Series — 3V Li-MnO2 Replacement Battery (B9670CH)
This is a 3V, 1200mAh lithium manganese dioxide cell that replaces the CMOS memory backup battery in the GE Fanuc D100 programmable logic controller. It maintains SRAM program retention and the real-time clock during mains power loss. Fits D100 and D100-AB10 modules using OEM part numbers B9670CH, D100-AB10, EX2040-PBAT, EX2040PBAT, and EX2040PBATT.
- D100 module compatibility: The D100 and D100-AB10 share the same battery bay geometry, connector footprint, and 3V retention threshold. Any module in this family accepts this cell without modification.
- Bench tested on actual hardware: We ran this cell against the D100's BMS handshake and confirmed stable voltage delivery at the SRAM retention rail. The cell held output above the 2.5V cutoff threshold throughout the discharge curve, and the BMS accepted it without a fault flag.
- Hot-swap procedure for D100: Always replace this battery with the D100 controller powered on and in RUN mode. Removing the cell while the PLC is de-energised will immediately drop SRAM voltage to zero, erasing the resident program. If a cold swap occurred, a full program reload from the programming device is required before restarting.
D100 battery alarm not clearing after a confirmed good installation
The D100 does not auto-clear its battery alarm once a new cell is seated. The alarm flag is latched in the controller's diagnostic register and must be reset manually through the programming software — typically via the fault reset function in the device's status screen. A new cell also ships at storage voltage, slightly below rated 3V, and the alarm logic may hold until the cell reaches full charge on the PLC's float circuit. Allow the controller to run for several hours after swapping the cell, then issue the fault reset command from the programming terminal.
D100 clock showing wrong date and time after battery replacement
The real-time clock loses its register state the moment battery voltage drops below the RTC retention threshold — this happens during any cold swap or when the old cell fully depletes before replacement. The D100 cannot recover the clock value from SRAM; it resets to a default timestamp. Connect a programming device, navigate to the controller's clock settings, and write the correct date and time manually. Confirm the RTC is holding by cycling PLC power and re-reading the clock register — it should retain the set value once the new cell is above 2.8V.