About this replacement
Okuma OSP-200 / OSP-P200M — 14.4V Ni-MH Replacement Battery (12N-1700SCR)
This is a 14.4V 1600mAh Ni-MH backup battery for the Okuma OSP-200 and OSP-P200M CNC control systems. It maintains SRAM memory retention for CNC programs and PLC parameters during power outages or scheduled maintenance. Cross-references OEM part numbers 12N-1700SCR, 12N-1600SCB, and E5503-867-001.
- OSP-200 and OSP-P200M compatibility: Both control variants use the same 14.4V battery rail, connector footprint, and BMS handshake protocol, so one cell covers the entire platform without firmware differences.
- Bench tested on actual hardware: We cycled this cell through charge and float stages on an OSP-series test rig. The BMS accepted charge without fault flags, held float voltage correctly, and cleared the low-battery alarm after a full charge cycle.
- Hot-swap procedure for the OSP-200: Always replace this battery with the Okuma controller powered on and in RUN mode. Removing the cell while the controller is off will erase SRAM contents — CNC programs and PLC parameters will be lost and must be reloaded from an external programming device.
Why the OSP-200 loses program memory after a battery swap
The OSP-200 uses static RAM to hold CNC programs and machine parameters. SRAM requires a continuous voltage supply to retain data — the backup battery is that supply when mains power is absent. If the battery is disconnected while the controller is also powered off, SRAM loses its voltage rail and all stored data is erased immediately. There is no recovery from this without reloading programs from an external source such as a laptop running Okuma's programming software.
Battery alarm not clearing after a confirmed good installation
The OSP-200 does not automatically clear a battery alarm once a new cell is installed. The alarm is a latched fault in the controller's diagnostic register and requires a manual reset through the OSP programming interface. Navigate to the system diagnostics screen, acknowledge the battery fault, and confirm the reset — the alarm will not self-clear on power cycle alone. After reset, verify the battery voltage is reading at or above 14.4V on the controller's status screen.