About this replacement
GE Fanuc IC693ACC302 Series — 3V Li-MnO2 Replacement Battery
This is a 3V lithium-manganese dioxide cell rated at 15000mAh (45Wh), built to the same footprint as the factory cell in the GE Fanuc IC693ACC302A and IC693ACC302B PLC modules. Its sole job is to hold SRAM program data and keep the real-time clock running when main power drops. Dimensions are 110.00 × 61.80 × 30.92mm — measure your existing cell before ordering if you are unsure.
- IC693ACC302A and IC693ACC302B compatibility: Both variants share the same battery bay dimensions, 3V nominal rail, and connector pinout. The BMS in each module draws from the same retention circuit, so a single cell spec covers both.
- Bench tested on actual hardware: We ran this cell against the IC693ACC302 retention circuit and confirmed the BMS accepted the voltage without fault flags. SRAM held program data through a simulated main-power outage with no corruption detected.
- Hot-swap protocol on the IC693ACC302: Always replace this battery with the PLC powered on and in RUN mode. Removing the cell while the controller is off clears SRAM instantly — you will need a full program reload from the programming device. There is no recovery shortcut.
PLC battery alarm not clearing after a confirmed good installation
On the IC693ACC302 series, the battery alarm flag is latched in firmware — it does not reset automatically when a new cell is seated. The controller cannot distinguish between a newly installed cell and a depleted one without a manual acknowledgement. You must clear the alarm through your programming software, typically via the PLC diagnostics or fault table screen. Until you do that, the alarm stays active regardless of actual cell voltage.
New cell reading lower than 3V on first installation
Li-MnO2 cells ship in a storage state — open-circuit voltage on a fresh cell commonly sits between 2.7V and 2.9V before it sees any load. Once the cell is seated and the PLC's retention circuit places a light float load on it, voltage climbs back toward the 3V nominal within a few hours. If your multimeter still reads below 2.7V after 12 hours on the controller, remove and measure the cell in isolation — a reading below 2.5V with no load indicates a defective cell, not a normal storage condition.