How to Charge a Dead Battery
A word of caution about dead batteries. If your battery becomes totally discharged, you should re-charge it (for 3-4 hrs.) with a proper battery charger. Don't just jump it and expect your alternator to re-charge it.
Late-model cars take large amounts of current to operate such things as fuel pumps, fuel injection, PCM, and lots of other electricity-consuming accessories. That's why most cars have 100-amp or larger alternators. Running all that stuff, while trying to resuscitate a really dead battery, can make an alternator overheat and become damaged.
However, if you don't have a charger, start by hooking up the jumper cables to the two batteries and letting them "chat" for 30 minutes. Don't run the engine on the donor car. This will put at least some charge into the dead battery. Then start the donor car and let it run at fast idle for 10-15 minutes to add some more charge. Now start the dead car, but turn off as many accessories as you can (e.g., A/C, defroster, headlights, etc.) until the car has been driven for a couple of hours, on preferably an interstate (i.e., avoid stop-and-go traffic).
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