On Intel boards with two rows of 4 LEDs (e.g., labeled for high nibble and low nibble):

Use the CPUID CPU-Z utility to find the model name and chipset under the "Mainboard" tab. 2. Common Specs for "21 B6 E1 E2" Marked Boards

This board uses a standard CR2032 coin battery. If the board forgets time/date or gives "CMOS Checksum Error" on boot, replace this battery.