About this replacement
ABB 364-6731 / SB822 Series — 3.7V Li-Polymer Replacement Battery
This 3.7V, 3000mAh lithium-polymer cell provides backup power for SRAM and real-time clock functions in ABB programmable logic controllers. It fits the 364-6731, 3BSC760019E1, AB12G, and SB822 models. Without a live backup cell, program data and clock settings are lost the moment mains power drops.
- 364-6731 / SB822 platform fit: These ABB controller variants share the same memory backup circuit, connector pinout, and 3.7V nominal voltage rail. One cell covers all four model numbers without any adapter or wiring change.
- Bench tested on actual hardware: We ran this cell against the BMS handshake on the SB822 backup circuit. The cell accepted float charge immediately, held steady at 3.7V nominal, and the controller logged no battery fault events during the test cycle.
- Hot-swap is mandatory on this controller: Never remove the backup cell while the PLC is powered off. Always swap the cell with the controller in RUN mode and mains power live. Removing the cell from a de-energised PLC wipes SRAM instantly — a full program reload from the programming terminal is then required.
PLC battery alarm not clearing after a confirmed good installation
The ABB controller does not auto-clear a battery alarm once a new cell is seated. The alarm flag is written to a status register and stays latched until a technician resets it manually through the programming software. Connect the programming terminal, navigate to the diagnostic or status register section, and clear the battery alarm bit explicitly. Cycling power alone will not reset it.
New cell reading below 3.7V on the controller's diagnostic screen
Lithium-polymer cells ship at storage voltage — typically 3.5V to 3.6V — to slow degradation in transit. This is normal and not a fault. Once seated in the PLC, the backup circuit applies a gentle float charge and the cell rises to full nominal voltage within a few hours. If the reading stays below 3.5V after 24 hours on a powered controller, check that the cell connector is fully latched and the backup circuit is live.