fully charged battery dies within 8 hours

[Jim_McQueen]

I own a 1987 ford country squire and now I have to unhook the battery whenever I am not driving it.
This pisses me off.
Not to mention the battery itself is a brand new duralast.
I unhooked it last night and this morning I hooked it back on, the fucking battery was dead again!!!

It's got to be the alternator, right?

I think maybe something is short-circuited.

What in the hell should I be fucking looking for?!

[Fritz The Cat]

How do you know the battery is dead? Does the car not turn over? Have you turned on the headlights to see if they come on brightly or dim? Did you try to start the car again after you shut it off but before you disconnected the battery? It could be battery, voltage regulator, alternator, cables, or starter. Need more info to narrow it down. Try the above things and get back to us.

[pcv]

You might have a bad alternator. Measure the voltage across the battery terminals with the vehicle running, it should be 13-14 volts. If not, its a bad alternator. If it is, then by the time you get home, the battery is depleted of charge. You disconnect it and reinstall it the next morning to a dead battery. It will not start. If the battery is charged and you disconnect it and the next morning it will not start, then you might have a bad battery. That has been know to happen. Don't be surprised. Another thing could be happening is that the battery is tall and is grounded by the hood, killing the battery. Check it out and good luck to you.

[Unit 5302]

The alternator most likely has a short in the internal rectifier (diode trio for you GM fans) and it's allowing current to cross back through the alternator the wrong way and dissipate through the car.

Take a test light or a good multitester. Disconnect the negative battery cable, and put the positive pin on the terminal, and the negative pin on the post.

The battery drain should light the test light up like a christmas tree and the drain should be over 1amp. Now disconnect the plug in on the alternator and try it again. If your drain drops dramatically, you've found the problem.

[christianrider]

If none of the above suggestions work, try this:

Make sure ignition is in the off position
Remove the positive cable from battery.
Next one by one, remove a fuse
go back and check with a test light betweent he positive cable and battery post.
If light does not come on, then move to your next fuse.
If it does, then you possibly have found the circuit that is giving you trouble.

I have done this in the past and it seems to work.

[hawkeye2100]

If its not a short in the internal rectifier, it maybe a bad fusible link...will cause the same problem...

[hondahappy86]

the same thing happened to me on a ford truck i used for work at the junkyard....yeah it was a junk yard vehicle....but anyhow...there is a little box thet controls the ignition system....sometimes these go bad....look under the hood....you should see it conected to your distributor ...check it out

[86bluethunder]

I am having the same problem i have a new battery,alternator, and all the fuse's are good. but when i take off the battery cable the car dies so what could the problem be. could the alternator be bad ?

[freeclimber]

If you have a battery that is known to have %100 charge and after a period of minutes or hours it dies, w/o being connected to a circuit that could drain it, then your battery is a dud.
If the %100 battery only dies when allowed to sit while connected to the vehicle's cables, check for parasitic drain.
If your battery is not properly charging during driving, check connections, etc. and alternator output.