When you check these three, always start with the battery. It's most often the part that failed, and it's also the cheapest part to replace. The Car Battery. A car battery should last about four to five years. It is not made to hold a charge for that long, so it gets recharged by the car's alternator while you drive.
(At 30 degrees F. a fully charged battery will measure about 12.588 volts, and at zero degrees F it will measure about 12.516 volts.) CHECK BATTERY CHARGING VOLTAGE. After charging the battery or jump starting the car, connect the voltmeter to the battery the same as before and not the charging voltage.