Gould 884 PLC Replacement Battery 3V 1350mAh Li-MnO2

GOULD 884 / 984X-008 / ASC11 — 3V Li-MnO2 Replacement Battery

This is a 3V lithium-manganese dioxide cell rated at 1350mAh, replacing the internal backup battery in GOULD 884, 984X-008, ASC11/BASIC, and B885 programmable logic controllers. It powers the real-time clock and SRAM memory retention circuit, keeping program data intact when mains power drops. Without a healthy cell, the PLC loses its program and clock on every power interruption.

• 884 and 984X-008 series compatibility: These controllers share the same 3V lithium cell format and memory backup architecture. The voltage rail feeding the SRAM retention circuit is identical across the 884, 984X-008, ASC11/BASIC, and B885, which is why one cell covers all of them.
• Bench tested on actual hardware: We verified open-circuit voltage on arrival and confirmed the cell holds above 3.0V under the low-current SRAM retention load. The BMS handshake on these controllers is passive — no digital authentication required.
• Hot-swap rule for GOULD PLCs: Always replace this battery with the controller powered on and in RUN mode. Removing the cell while the PLC is de-energised wipes SRAM instantly. If the PLC was off during the swap, a full program reload from the programming device is required before restarting.

GOULD 884 losing program memory after battery swap

The 884 uses volatile SRAM for program storage, and the backup cell is the only thing keeping it alive when mains power is absent. The moment the old cell is pulled and the new one is not yet seated, SRAM power collapses — that window is enough to wipe the program entirely. Even a two-second gap during a cold swap is sufficient for data loss. The only recovery is reconnecting the programming terminal and downloading the program again from a saved project file.

Battery alarm not clearing after the new cell is installed

GOULD and Modicon-lineage PLCs do not auto-clear the battery fault flag when a fresh cell is seated. The alarm bit is latched in the controller's status word and requires a manual reset through the programming software — typically by writing a zero to the battery fault bit in the status file or sending a clear-faults command. Confirm the new cell reads above 2.8V on a multimeter first to rule out a genuinely flat replacement. Once the bit is cleared in software, the alarm light should go off immediately.