Mitsubishi GT11-50BAT CMOS Backup Battery 3V 550mAh

Mitsubishi GT10 / GT11 Graphic Terminals — 3V Lithium CMOS Backup Battery (GT11-50BAT / FX3U-32BL)

This is a 3V, 550mAh lithium coin-cell battery that replaces the CMOS backup cell in Mitsubishi GT10, GT11, and GOT 1000 series graphic terminals. It maintains SRAM configuration data and the real-time clock circuit when mains power is removed. Without a functioning cell, the terminal loses its settings and resets the clock to a default date on every power cycle.

• GT10, GT11, and GOT 1000 compatibility: All three series use the same physical cell format and 3V retention circuit. The SRAM and RTC draw power directly from this cell the moment mains power drops, so cell voltage must stay above 2.8V to prevent data loss.
• Bench tested on actual hardware: We verified the cell holds 3.0V under the low-current standby draw of the GT11 RTC circuit. The terminal retained its project data and clock value through a sustained mains-off period without a single checksum error on restart.
• Post-installation clock correction: After swapping the cell, navigate to the GT terminal's clock settings and enter the correct date and time, then confirm the save. The RTC circuit loses its reference the moment the old cell is removed, so the clock will show a default value until it is manually corrected.

Settings lost every time mains power is removed from the GT terminal

The GT10 and GT11 terminals rely on this cell to hold SRAM contents the instant AC power drops. When the cell voltage falls below the 2.8V retention threshold, the SRAM loses its charge within seconds of mains disconnection. The terminal then boots to factory defaults, and any project or clock data written before the outage is gone. Replacing the cell and re-entering settings is the only fix — there is no battery reconditioning step for a depleted lithium primary cell.

CMOS checksum error appearing on GT terminal boot after cell swap

A checksum error immediately after a new cell is fitted usually means the terminal read corrupted or blank SRAM — not a faulty replacement cell. This happens when the old cell was fully depleted before removal, wiping the stored configuration. Check that the new cell is seated flat with firm contact against the spring clip; a tilted cell can read as low voltage. Once seated correctly, clear the error through the terminal's initialisation menu and re-enter the project settings.