Problem guide
Car battery won't hold a charge? Find the cause first.
Repeated discharge can point to an aging battery, charging-system trouble, parasitic draw, connection problems or other faults. Reconditioning is only one possible path.
Common diagnostic buckets
Battery condition
Age, deterioration, sulfation or internal failure can reduce usable capacity.
Charging system
An alternator or charging fault can leave a serviceable battery undercharged.
Parasitic drain
An electrical load can discharge the battery while the vehicle is off.
What to do next
Inspect the battery, verify connections and obtain an appropriate battery/charging-system test. If the battery is merely discharged, recharge and retest according to manufacturer guidance. If it fails appropriate testing or is unsafe, replacement is generally the practical route.