Im sure this has probably been beat into the ground but i cant seem to find the exact answers im looking for. i have a 03 volvo s 60 2.4t. couple of days ago went to get into the car and it would not start. the battery was dead. had a friend give me a jump and car started right up and drove home fine. went to start car next morning same thing battery is dead. put it on a battery charger and charged it to 100% and drove too work and back no problem. checked the battery percentage when i got home and it was almost dead again. fully charged it that night and let it sit till morning and battery was still 100% when i checked it in the morning so i know its not draining while parked and not driving. my first thought was a bad altornator because the battery was only discharging while being driven but from other reasearch ive done says that if the altornator is bad then the car will die on you while driving not allow you to drive all the way home and just not start again after its been parked. anyone else know a bit more about this? again i apologize for bbringing up an old topic but nothing i have found tells me much about my symptoms and whats likley to be the cause for them.

 

A modern vehicle has multiple systems that are draining the battery of energy while the car is running. The starter uses a large amount of amperage to crank the engine but, that load is temporary. The ignition system, electric fuel pump, a/c, and all of the numerous accessories are constantly draining the battery. The car will run on the battery alone until there is insufficient voltage to fire the ignition and run the fuel pump. If the alternator is not putting out the rated amperage then you will see the symptoms that you have described.

 

You can drive your car without an alternator if the battery is good. You can drive maybe 30 minutes or so. Charge the battery and drive to an auto parts store to have it checked. Here are a couple of questions you can ask yourself to trouble shoot the situation:
1. Is the serpentine belt attached?
2. Is several dash warning lights on while driving?
3. Are the battery cable connections clean and tight?
4. Are the battery cables in good condition or are they broken somewhere?