Why is my car not start and battery being low most time and discharge

remove your battery and hook it up to a external charger until full charge. If this is an AGM battery then make sure you select the AGM setting for charging. Once fully charged reinstall battery and see if error goes away (this is a mandatory procedure as a non fully charged battery can cause this issue).

If issue is still present then the alternator likely isnt exciting or theres an issue with communication to the cars computer. check all wires leading to and from alternator. Check underbody of car for grounding wires (corroded wires can cause bad ground).

If still no change remove alternator and have it tested.