How to fix a computer that say system battery voltage is low

Symptoms of a CMOS battery issue are a loss of BIOS/CMOS settings and the clock always needing to be reset.

This could also be a sign of a failing UPS (uninterruptible power supply) battery. Is this system connected to an UPS? If so, switch to the surge suppressor side or a power strip until you replace the UPS battery or the UPS itself.