About this replacement
Dell Latitude 3330 / E-Series — 3V Lithium CMOS Backup Battery (0928.13)
This is a 3V 220mAh lithium coin cell that replaces the OEM CMOS backup battery on the Dell Latitude 3330, E4310, E5420, and E6410 motherboards. It maintains the RTC circuit and BIOS SRAM when mains power is removed. When this cell drops below the 2.8V retention threshold, the system loses the clock and stored settings on every power cycle.
- Latitude 3330 and E-Series compatibility: These models share the same motherboard socket format and RTC circuit voltage requirement. The 0928.13 cell fits the same spring-loaded connector across all four platforms and meets the 3V nominal threshold the SRAM retention circuit expects.
- Bench tested on actual hardware: We seated the cell in the Latitude 3330 socket, cycled mains power repeatedly, and confirmed the RTC held the correct time and BIOS settings across each cold boot. The cell held above 2.9V under load throughout testing.
- Post-install BIOS correction: After fitting the new cell, enter BIOS setup immediately and set the correct date and time, then save and exit. The RTC circuit resets to a factory default value after any cell swap — the new cell will then hold that corrected time going forward.
BIOS clock resetting to 2000 after every power cycle
The Latitude RTC circuit draws from the CMOS cell continuously when AC power is absent. Once the cell drops below 2.8V, the SRAM can no longer retain the clock value through a cold boot. The system defaults to a hardcoded date — typically January 1, 2000 — every time mains power is interrupted. Replacing the cell and manually re-entering the correct date in BIOS resolves this immediately.
CMOS checksum error on boot after fitting a new coin cell
A checksum error on first boot after a cell swap is normal — the BIOS detects that stored settings no longer match the checksum it computed before the old cell failed. The new cell is not faulty. Enter BIOS setup, confirm or re-enter your settings, save, and exit. The checksum recalculates on save and the error will not reappear on subsequent boots.