Try to Restart Your Car
Even if you have successfully restarted your dead car, you do not want to shut it off for fifteen to twenty minutes. The cars alternator puts power back in slowly, and the battery will not be fully charged until it has about 500 amps stored in it. This could take over an hour for a full charge.
After you have let your jump started car run, or you have driven your car for a minimum of twenty minutes, turn off the engine and see if it will restart on its own without any cables. This is a good test to make sure the charging system is working and a good indicator that you will not get stranded on your way home.
If the engine does not crank on its own, you’ll be jump starting your car again, and you may want a buddy to follow you to your next location. Additionally, If your car won’t start again on its own, this is a good sign that something is actually wrong with the battery or the charging system and should be checked by your mechanic.
If This is a Car That You Are Thinking of Buying
If this is a car you may want to buy, have the dealer fix it before you test-drive the car. Get it in writing that the car had a dead battery when you first looked at it, and the dealer agreed to fix it at no charge and make him warranty that repair in writing.
If you just bought the car, report this to the dealer as soon as you can. Many dealers need to jump a car that has sat for a long time, and the battery can be damaged from sitting with low voltage.
When buying a new or used car, many electrical parts can be damaged from dead batteries or salesmen that don’t know how to jump a car correctly.
If you have recently purchased a car, and you have computer problems, starter motor or alternator failure, battery failure or any electrical related issues. Report this to the car dealer, or you could be a victim car buying scams.
One indicator of a car that has a history of battery problems is to check the battery posts and cables. If it has many scratches on them from jumper cables, the car has had been dead many times and needs to be fixed before you close your new car purchase. Alternatively, if you already bought the car, you may want to review our “After The Sale” guide.