Cutler Hammer A02B-0130-K106 PLC Replacement Battery 3V 5000mAh

Cutler Hammer A20B-0130-K106 — 3V Li-MnO2 Replacement Battery (A02B-0130-K106)

This 3V 5000mAh lithium manganese dioxide cell is the backup power source for the Cutler Hammer A20B-0130-K106 PLC controller. It holds SRAM program memory and keeps the real-time clock running during mains power loss. Replace it before voltage drops below threshold — data loss in a PLC is not a minor inconvenience.

• A20B-0130-K106 controller compatibility: This cell matches the voltage rail, physical footprint (51.56 × 27.15 × 25.60mm), and connector spec of the A20B-0130-K106 memory backup circuit. The BMS on this controller monitors cell voltage directly — wrong chemistry or voltage triggers a battery alarm that won't clear.
• Bench tested on actual hardware: We ran this cell under the low-drain float conditions a PLC backup circuit uses. The BMS accepted the cell without alarm, SRAM retention held across simulated power interruptions, and the RTC maintained accurate time throughout the test cycle.
• Hot-swap requirement — read before touching the cell: Always replace this battery with the PLC powered on and in RUN mode. Removing the cell while the controller is off wipes SRAM. If that happens, a full program reload from a programming device is the only recovery path.

SRAM retention voltage threshold on the A20B-0130-K106

The A20B-0130-K106 uses a dedicated SRAM backup circuit powered solely by this cell during mains-off conditions. Li-MnO2 chemistry holds a stable discharge curve near 3V through most of its capacity, then drops sharply. The PLC battery alarm typically triggers when cell voltage falls below roughly 2.7V — but SRAM retention can fail before the alarm fires if the cell is already degraded. Replace at the first alarm, not after the second.

Battery alarm not clearing after fitting a new cell

The A20B-0130-K106 does not auto-clear its battery alarm when a new cell is installed. The alarm flag is set in controller memory and must be manually reset through the programming software — fitting the new cell alone will not do it. Connect a programming device, navigate to the battery alarm parameter, and clear the flag explicitly. If the alarm returns within hours of clearing, check cell voltage at the connector — it should read at or above 2.9V after the float charge settles.