Yamaha TS-X PLC Replacement Battery 3.6V 1650mAh

Yamaha TS-X / KCA-M53G Series — 3.6V Li-SOCl2 Replacement Battery (TLP-97311/A/ST)

This is a 3.6V 1650mAh lithium thionyl chloride cell for the Yamaha TS-X programmable logic controller and KCA-M53G / KCA-M53GO-10 units. It backs the SRAM program memory and real-time clock during mains power loss. OEM part number TLP-97311/A/ST cross-references directly to this form factor and voltage rail.

• TS-X and KCA-M53G platform fit: These controllers share the same backup circuit architecture — 3.6V rail, identical connector footprint, and the same BMS float-charge threshold. One cell covers all three models listed.
• Bench tested on actual hardware: We ran this cell under a simulated PLC backup load and confirmed the BMS accepted the float charge without a voltage fault. Open-circuit voltage at dispatch sits at storage level — expect it to rise to full within a few hours on the controller's charge circuit.
• Hot-swap procedure for TS-X memory retention: Always replace this cell with the PLC powered on and in RUN mode. Removing the old cell while the controller is off will wipe SRAM immediately. If the PLC was off during the swap, connect a programming device and perform a full program reload before returning to production.

Why the TS-X loses program memory after a battery swap

SRAM on the TS-X has no secondary hold-up capacitor of meaningful size. The moment the backup cell is disconnected and the mains supply is absent — or even briefly interrupted — SRAM voltage collapses and the stored program is gone. This is not a fault with the cell; it is the architecture of the backup circuit. Hot-swapping with the PLC powered on and in RUN mode is the only way to bridge the gap between old and new cell without losing data.

Battery alarm not clearing after the new cell is installed

The TS-X battery alarm flag is latching — it does not reset automatically when a new cell is detected. After installing the replacement and confirming mains power is live, open the programming software, navigate to the controller diagnostics or alarm log, and manually clear the battery fault bit. If the alarm returns within 24 hours, check enclosure temperature — ambient above 40 °C roughly doubles the self-discharge rate of Li-SOCl2 cells and will trigger the low-voltage threshold ahead of the expected service interval.