Big Battery Botheration

[Alexlind123]

During the school year, when i am driving my car every day, the battery operates in a satisfactory manner. During this time, the car does turn over for about 2 seconds before starting, which may or may not be a related issue, so dont let that confuse the problem.

During the summer, if i dont drive the car for 4four days, it will not start. The battery drains to a point where it wont start over a period of no less than 4 days.

From searching, i have found that problems like these generally tend to be one of three things:

A) The alternator. Something tells me this isnt likely, because of the nature of the problem.

B) The battery. Old batteries may just not hold their charge for a long enough period of time.

C) A current drain somewhere in the car.


So my question is, where should i start? Also, how do i check for a current drain? I do have access do a multimeter, but i dont know how to use it.

[632 Regal]

I agree with all 3 in your case.

how old is the battery?

the drain could be through a diode in the alternater itself.

disconnect the neg terminal and read the voltage of the battery then after its connected. theres a way to tell the voltage drop but at this moment it escapes me.

check and compare sitting voltage vs running voltage to see if the alt is producing enough voltage to charge.

[shogun]

written by Javier

If you are a beginner in electric issues, this walks you through it, hopefully:

I'll try to make it simple, ...

The meter should have an A scale (Ampere) for reading current. Preferably, a High amp one (10A for example). In some of them, this high amp scale requires the red plug of the wire probes to be connected in a different hole. We do not know the magnitude of the current involved, so in order to preserve the meter, it is better to start reading in this high amp scale.

Disconnect the ground (negative) lead to the battery (electronic devices in the car will loose status when battery is unplugged, so you will need radio code for example), connect the positive (Red) meter probe to the negative thick wire to the battery, and connect the negative (Black) probe of the meter to the negative battery post. Be sure that the probes are inserted in the proper holes in the meter for the readings (Amp) you intend to take.

If you have a leak as you assumed before, you should have a significant reading in the meter (maybe/sometimes more than 50 milli amps, > 0.05 Amp). If the selected scale do not allow you to have a clear reading of the leaking current and you want to change down scales, do so. Remember that some meters require to select a new hole in the meter for the red probe in order to select a lower Amp (Current) scale.

Once your meter is properly set and you have a good steady reading of the leaking current, proceed to remove, one by one, the fuses on the fuse box. Keep an eye to the meter in order to identify which fuse removal is dropping down the current in the meter. The leaky circuit is feed by that fuse.

Investigate what devices are associated to that fuse, plug the fuse back, and start disconnecting all devices one by one until you get again a reading drop. That device would be the culprit.

Written by Javier, and slightly changed by me to fit such question in general.
Hope that helps.

[Alexlind123]

Thanks alot Shogun! i will try just what you said. Your help was also appreciated, jeff =D