SBC loosing BIOS or system clock running slow
If you use an Embedded systems SBC and find that the BIOS settings are not being retained after powering off the system or you notice that the system clock is running slow.
Try replacing the CMOS battery. The battery voltage of most SBC cards should be greater than 2.6 volts, with a new battery registering close to or greater than 2.9 volts in the circuit. Other things to verify would be to check for contamination causing the battery not to make good connection to the battery clip. On conformal coated boards there needs to no conformal coating under the battery clip connectors. If the voltage of the battery and connections look good, you may need to return the board for repairs.