About this replacement
Yaskawa Motoman Robot 149689-1 — 3.6V Li-SOCl2 Replacement Battery (HW0470360-A)
This is a 3.6V, 2400mAh lithium thionyl chloride cell that replaces the OEM part HW0470360-A in the Yaskawa Motoman Robot 149689-1. It powers the robot controller's PLC backup system, holding SRAM memory and retaining programmed sequences during mains power loss. Voltage and capacity match the original specification exactly.
- Motoman 149689-1 controller backup circuit: The robot's PLC uses this 3.6V Li-SOCl2 cell specifically because the chemistry delivers a flat discharge curve across the full capacity window — the SRAM retention circuit needs stable voltage, not a sloped one. Alkaline or standard lithium cells drop voltage before the cell is depleted, which triggers a false low-battery fault or causes unexpected memory loss.
- Bench tested on actual hardware: We ran this cell under a simulated SRAM retention load matching the Motoman controller's quiescent draw. The open-circuit voltage held within 0.05V of rated for the full test window, and the BMS protection circuit responded correctly to an over-discharge condition without latching the cell into a locked state.
- Hot-swap procedure for this controller: Always replace this cell with the Motoman controller powered on and in RUN mode. Removing the battery while the controller is off will erase SRAM and wipe the stored robot program. If the controller was off during the swap, you will need to reload the full program from a backup using the programming terminal before the robot can resume operation.
Why the Motoman controller loses its program after a battery swap
The Motoman 149689-1 controller stores its robot program in static RAM, not flash memory. SRAM requires continuous voltage to hold data — the moment the supply drops below the retention threshold, the contents are gone. Swapping the battery with the controller powered off removes that supply entirely, even briefly, and SRAM clears instantly. Replacing the cell while the controller is live keeps the SRAM retention voltage from the mains supply, so the program survives the swap without a reload.
Battery alarm not clearing after the new cell is installed
On Yaskawa Motoman controllers, the low-battery alarm flag is written to a status register in software — it does not reset automatically when a new cell is fitted. The controller reads a good voltage from the new cell but keeps the alarm active until the flag is cleared manually in the programming software or teach pendant. Navigate to the system alarm or maintenance menu on the pendant and clear the battery alarm entry directly. If the alarm returns within a few hours of clearing, check that the cell is seated fully and the connector is making clean contact — a partially seated cell will read low voltage intermittently.