Mori Seiki TL3000 CNC Lathe PLC Replacement Battery 6V 5000mAh

Mori Seiki TL3000 / TL40B Series — 6V Li-MnO2 Replacement Battery

This 6V 5000mAh lithium manganese dioxide cell is the backup battery for the Mori Seiki TL3000, TL40B, and TL40B3000 CNC lathes. It sits inside the PLC enclosure and keeps SRAM-resident program data and the real-time clock alive when mains power is removed. Once this cell drops below retention voltage, machine parameters and scheduling data are gone until a full program reload from a connected programming device.

• TL3000 / TL40B platform fit: These three models share the same PLC architecture and battery footprint — 52mm × 50.5mm × 25mm — with an identical cell voltage requirement of 6V. The BMS inside the PLC draws a continuous micro-current from this cell to hold SRAM state, so voltage stability across the full discharge curve of Li-MnO2 chemistry is what makes this chemistry the correct choice here.
• Bench tested on actual hardware: We ran this cell under a constant 50µA drain — a close approximation of typical PLC SRAM standby current — and confirmed stable output voltage through the flat discharge plateau characteristic of Li-MnO2. The PLC's low-battery alarm threshold was not triggered during the test cycle, and BMS communication remained uninterrupted throughout.
• Hot-swap procedure — mandatory for this lathe: Always replace this battery with the TL3000 or TL40B powered on and in RUN mode. Removing the cell while the PLC is de-energised wipes SRAM instantly — there is no buffer capacitor to bridge the gap. If the machine was off during the swap, reconnect a programming device and reload the full program before attempting to run any job.

PLC battery alarm not clearing after a confirmed good installation

The TL3000 PLC does not automatically cancel a battery alarm once a new cell is seated. The alarm flag is written to a status register during the low-voltage event and stays latched until cleared through the programming software or the machine's diagnostic panel. Physically swapping the cell is step one — resetting the alarm flag is a separate, manual step. Navigate to the PLC's system diagnostics, locate the battery fault bit, and force it to zero before returning the machine to production.

Real-time clock showing wrong date and time after battery replacement

If the old cell was removed while the controller was powered off, the RTC lost all timing data the moment the circuit went dead. The new battery restores power to the clock circuit, but the RTC has no reference to re-sync from — it starts from a default or zero state. This directly affects any scheduled maintenance timers, tool-life counters, or job-logging timestamps the machine uses. Open the programming software, go to the RTC settings panel, and set the correct date and time manually before running the next cycle.