If I drive my car at like 8pm my battery will be fine the next day. But if I don't drive after I get off work at 4 then the next day it won't start.I will have some power like the light under the hood. It always starts when I jump it.I had my alternator tested and it's fine. The same goes for my battery.Any ideas?
I would first look for something that is staying on when it should not be. look for dome lights, glove box lights, trunk, or under-hood lights. also check things like aftermarket stereos (especially amps) that are not connected right.
Replace worn Battery cables and check ground wire for open current
there has to be a short someplace ! if the starter gets a short it in then it will drain the battery because the hot cable runs down to the starter ! unhook the hot cable the night before and the next morning hook it back up and see if it starts !
You have a short in the electrical system that's draining the power over time, if your batt and alt are both good.
There is a short. You need a voltmeter with an amp setting. Disconnect the negative battery cable. Put one voltmeter lead onto the negative battery post and another onto the negative battery cable. If you read more than 50 mA it is being drained through a short. 0-10 mA is more typical. Find the fuse box inside the car, often near the brake pedal, and start pulling fuses one by one until the short disappears. Find the name of the fuse connected to the short and that's where your problem is. Next remove/replace/fix that component. As a temporary solution you may leave that fuse out if the component is not essential. If you don't understand the name of the fuse then try google. If you don't want to get a voltmeter then disconnect the negative battery terminal when you aren't driving the car, then reconnect when you need it. This will prevent any power drain. Take it to a mechanic and he'll know how to do the above quickly and easily.
