Why is my battery is loosing its charge with a new alternator?

Answer 1

either the battery is bad or you have something draining your battery when the car is shut off.

Answer 2

You could have a shorted cell in the battery. You could also have some other short that is draining the battery. Some wire going to ground. Are there any accessory's on?

If you have an ammeter put it in series with the battery and note the draw. Then have a friend pull a fuse and see if there is any difference in the current draw. Pull them one at a time and they replace the fuse before pulling the next. If you have a short this will narrow it down to a specific circuit that you could trouble shoot..

Answer 3

You most likely have a parasitic load. In other words, something is staying on after you turn your car off. Check your glove box light, your interior lights, etc. Another thing you can do is pull fuses and push them back in. Anything drawing power will cause a small park when the contacts touch again. This will at least give you an idea as to what circuit your problem lies in.

Answer 4

when you put a new alternator in, it is very important that the battery is fully charged or it will kill the new alternator. check the battery voltage when the vehicle is not running. then start the vehicle, the voltage should be around 14V.

Answer 5

if your battery is more than 3 years old it probley is loosing its holding power to hold a charge, Try a new battery and make sure all connections are tight. good luck

Answer 6

first thing to do is have both checked by a qualified person to make sure each is doing their job, second is to make sure all is connected properly and clean, bad or dirty connections will most certainly fail!

Answer 7

maybe the voltage regulator is bad? have that checked out.