Battery can't hold long?
 

Hi,

I would like to ask your help and any your ideas are so worth to me. My mustang CVTB 2000, if I don't drive a car for one day, the next day my car's battery is empty. And if I disconnect a battery, and leave it for months, and when I drive I reconnect battery again, my car run OK. So I have to disconnect and reconnect the battery for every weekend or when I don't drive for a day that is real a pproblem. I wonder any one might help me in this problem?
Many Thanks,

Ok so you have a voltage leak somewhere.. has the wiring been tampered with a lot? You know stuff like adding gauges, sterios, alarms, stuff like that?
Leave the battery connected but pull out a few fuses. Wait a day & see if it starts. If it does then you've just narrowed down the source of the voltage leak. if not, then repeat with some other fuses.

If it's killing the battery flat in one day. You have a major draw, like a couple amps or more.

Get an ammeter. Connect it in series with your battery. With the key off you should see a reading on the gauge. If you don't, it may be due to the draw being too small to register on the gauge. In that case use a multimeter.

Pull fuses one at a time, until the meter reads milliamps. It will not go to zero due to computer memory, radio memory etc.

Start with the aftermarket accessories, then to loads that can be on with the key off. Like glovebox light, sunvisor lights, trunk light, etc.

You have whats called a parasitic draw. Here are some pretty simple steps to track it down: http://www.wikihow.com/Find-a-Parasitic-Battery-Drain