Battery not holding charge?

[88LX-iSedan]

Well, i made a post about jumping my car not to long ago.. well that went fine but, i went back out after a few weeks to crank my car again and it made just a clicking noise and the engine light was just blinking fast. Once i tried to turn it over all lights went out, completely dead... turn off & back on, same thing. ..So why is the battery dying when i'm not driving it any? Only thing i can think of is the battery is gone or, it's the alternator.. maybe

[zero.counter]

You may have something discharging the battery like an accessory or stereo amp. Also, when you jumped the car, did you ever take it to check if it can still hold a charge or needed to be recharged?

The alternator can be tested as well, but is prolly not the issue...at least until you have thoroughly searched the whole bad battery issue.

[Mac]

Well if you're not driving the car the battery can't get charged. I'm pretty sure that even a good battery will go dead after sitting for a while. Even though it's a small draw the clock has a constant memory and I think the ECU does too. Also there could be something on all the time, like a trunk light that you might not notice.

[88LX-iSedan]

I removed all the stereo stuff (Amps & H/U), but it still does it so, i'm not sure what could be draining it. ..No i didn't get it tested either

Edit: No lights are on, dome & doors checked, trunk & tails check, head & park lights.. well those are obvious , it has sat for a long time though.

[dXsquared]

didnt have to do that!!

take the - off, put a test light inline.. if theres light with all the doors closed, you have a draw.. find it and your dead battery problem will be gone

Travis

[zero.counter]

didnt have to do that!!

What if it will not hold a charge due to bad cells?

Anyways, a pro way to measure parasitic draw, would require a digital volt / ohm meter. Most meters can handle around a 10 amp current flow. Disconnect the negative battery cable, set the meter on the appropriate scale, and connect it in series - inline between the battery cable and the battery itself...only. This should be done with everything turned off (obviously) - keys out, doors closed. Allow enough time for the illuminated entry system to power down. Measure the amount of current flowing through the meter and keep in mind.
In order to isolate the circuit with the draw, start removing fuses, one at a time, until the draw disappears. Remember, if you have a door open, the courtesy lamp circuit activates, and your readings will be inaccurate. To work with door open, you'll need to fashion something to hold the door pin switch down. Once you find the fuse that causes the draw to disappear, figure out what devices are on that circuit, and unplug them directly. This works all of the time!

[88LX-iSedan]

Thanks zero, copy, paste, save.. I'll try that, should i pull the fuses both under the dash and hood? ..Anyway, it could very well be that the car has just sat so long without being ran/driven that the battery is gone, because it has been sitting for around a year with the battery hooked up.. sooo ..Thanks to you, Mac & dX as well.

[Blkblurr]

Put a battery charger on it over night. If it starts a day or so later the battery is holding a charge. This means you probably have something draining the battery as mentioned before. When cars sit the battery gets drained due to power requirements of the ecu, clock, radio etc. This is normal but your battery should last for a month or two if it has a good charge to begin with.

[Oyvind Ryeng]

Also keep in mind that a standard battery is nothing but scrap when it has been completely drained of it's energy and not recharged immidiately. The only batteries I can think of that can survive this is the Optima Yellow/Redtop.