Data Star 48650 PLC Backup Compatible Battery 3.6V 2700mAh

Data Star 48650 — 3.6V Li-MnO2 Replacement Battery

This is a 3.6V, 2700mAh lithium manganese dioxide cell for the Data Star 48650 PLC. It powers the SRAM backup and real-time clock circuit, keeping program data and timing intact during mains power loss. When this cell depletes, the controller loses both memory retention and accurate clock function on the next outage.

• 48650 PLC backup rail: The 48650 uses a dedicated low-current backup rail fed directly by this cell. Li-MnO2 chemistry holds a flat discharge curve across the 3.0–3.6V range that SRAM and RTC circuits require. A lithium-ion cell would trip the BMS under the micro-amp standby load this circuit draws.
• Bench tested on actual hardware: We ran this cell under a simulated SRAM retention load and confirmed stable voltage across the full discharge curve. The cell held above the 2.8V SRAM floor throughout. No voltage sag, no BMS interrupt on the standby draw profile.
• Hot-swap procedure for the 48650: Always replace this cell with the PLC powered on and in RUN mode. Removing the battery while the controller is off clears SRAM instantly. If you swapped it during a power-off, a full program reload from your programming device is required before restarting the process.

PLC losing program memory after battery swap

SRAM in the 48650 has no capacitor buffer to bridge a battery change. Once voltage drops below the retention threshold — typically around 2.8V — memory clears in milliseconds. This happens if the cell is removed while the controller is off, or if the new cell is seated slowly enough to break contact. If your PLC faulted after the swap, connect your programming device and reload the last saved program file before attempting to restart production.

Battery alarm still active after fitting a confirmed good cell

The 48650 does not auto-clear a low-battery alarm once a new cell is installed. The fault flag is latched in the controller's diagnostic register and must be reset manually through your programming software. Navigate to the diagnostics or system status screen and acknowledge or clear the battery fault. Until that step is done, the alarm will persist even with a fully charged cell seated correctly.