Medion Akoya Mini E1210 CMOS Compatible Battery 3V 200mAh

Medion Akoya Mini E1210 — 3V Lithium CMOS Backup Battery

This is a 3V lithium coin cell, 200mAh (0.6Wh), fitted to the Medion Akoya Mini E1210 netbook motherboard. It powers the real-time clock (RTC) circuit and retains BIOS settings when mains power is disconnected. When this cell depletes, the netbook loses the date, time, and saved configuration on every power cycle.

• Akoya Mini E1210 motherboard fit: This cell measures 20.00 x 20.00 x 3.80mm and seats into the CMOS socket on the E1210 board. The flat lithium chemistry matches the voltage rail the RTC circuit expects — 3V nominal, with a retention threshold of 2.8V minimum before the SRAM loses its state.
• Bench tested on actual hardware: We verified cell voltage at dispatch. Fresh cells measure between 3.0V and 3.3V under no-load conditions. The RTC circuit draws microamps in standby — this cell handles that draw without voltage sag at the retention threshold.
• Post-install BIOS step: After fitting, enter the BIOS immediately and set the correct date and time, then save and exit. The CMOS cell powers the RTC circuit, so any gap in power during the swap resets the clock to a factory default value that must be manually corrected.

BIOS clock resetting to 2000 after every power cycle

The E1210 RTC circuit requires a minimum of 2.8V from the CMOS cell to hold its state. Once the cell drops below that threshold, the SRAM backing the clock and BIOS settings loses power the moment the mains cable is pulled. The chip resets to a hardcoded default — typically January 1, 2000. A depleted cell will not recover. Replace the coin cell, then set the correct date and time in BIOS and save before closing the lid.

CMOS checksum error on boot after fitting a new coin cell

A checksum error immediately after installing a new cell usually means the BIOS detected that stored settings no longer match the checksum it saved — because the previous cell died and wiped SRAM completely. The new cell itself is not faulty. Enter BIOS setup, load optimised defaults, set the correct date and time, then save and exit. The checksum recalculates on save and the error clears on the next boot.