Jeep Wrangler Forum

Jeep Wrangler Forum (http://www.wranglerforum.com/)
-   YJ Tech Forum (http://www.wranglerforum.com/f218/)
-   -   Battery killer (http://www.wranglerforum.com/f218/battery-killer-257986.html)

OverkillYJ 07-24-2013 08:33 AM

Battery killer
 
My battery is about 8 months old. Something recently started draining it when I park for a couple of days or more. Not sure if my battery is going dead or what. It almost seems like something is drawing a small amount of power all the time. I dont see anything though. Anyone know of the best way to figure out what it is/ Alternator is new as well. So is all of my wiring.

jeff_in_rc 07-24-2013 09:03 AM

First thing I would do is charge the battery then measure the voltage at the battery, should be 12.6 or so but it could be a little higher or lower. Then start the engine and measure the voltage again, should be 13+ volts and could be as high as 14.4 or so.

That will tell you if the alternator is working correctly. Then to check if there is a drain disconnect the ground lead and measure the voltage between the cable and the post, be sure to use a low setting on your VOM. If you have drain you should find it this way.

goatman 07-24-2013 11:07 AM

Another easy way to see if the battery itself has an internal short (if the thing sits for days regularly) is to just disconnect the battery after verifying it is charged. if you come back a few days later and it starts up fine, you have a voltage draw when the ignition is off.

OverkillYJ 07-24-2013 11:20 AM

I am guessing I could have damaged it using my winch and stuff. I am not familiar with internal shorts in the battery. I do have a gauge permanently hooked up to my battery so I do know that my voltage is correct. First thing I will do is what you said. I will get it charged then let it sit disconnected for a few days and see if it still starts.

Defcon 1 07-24-2013 09:51 PM

I am in the middle of working the same exact problem man. With my AUX equipment connected to the battery, my Jeep will last about 6 days before it won't start. With the AUX equipment disconnected, it'll last weeks. I went about it trying to isolate what ciruit is causing the parasitic draw. I've replaced 2 batterys so far ( both under warrenty ), thinking it was the battery, but I found it wasn't because I did this test:

If you take off the negative battery cable only, you can put an indicator light in between the negative terminal and negative cable. The indicator shouldn't come on, if it's dim or more-than-dim it means that some circuit is drawing power. You can also measure the exact voltage/amperage it's drawing with a digital multimeter, but a simple $10 test light will work too.

Get a digital multi-meter and do that test in current mode. One lead to positive terminal of batt, the other lead to positive cable. That will actually tell you how much current draw there is. You can then calculate (generally) the time it will take to drain your battery. From there you'll want to head to the fuse box and determine which circuit(s) is causing the draw. You'll know as the draw will be similar to that you found before. I'd also check the relays, first, as an easy step before unpluging and testing all the fused circuits. You can do that with the multi-meter as well.

I know a lot of guys won't tackle an electrical problem head-on like this, but if you're patient you will eventually figure it out. In the meantime, you can get a solar charger from Harbor Freight that plugs into the cigarette lighter, it will make up for voltage loss you currently have.

OverkillYJ 07-25-2013 09:08 AM

Quote:

Originally Posted by Defcon 1 (Post 4000164)
I am in the middle of working the same exact problem man. With my AUX equipment connected to the battery, my Jeep will last about 6 days before it won't start. With the AUX equipment disconnected, it'll last weeks. I went about it trying to isolate what ciruit is causing the parasitic draw. I've replaced 2 batterys so far ( both under warrenty ), thinking it was the battery, but I found it wasn't because I did this test:

If you take off the negative battery cable only, you can put an indicator light in between the negative terminal and negative cable. The indicator shouldn't come on, if it's dim or more-than-dim it means that some circuit is drawing power. You can also measure the exact voltage/amperage it's drawing with a digital multimeter, but a simple $10 test light will work too.

Get a digital multi-meter and do that test in current mode. One lead to positive terminal of batt, the other lead to positive cable. That will actually tell you how much current draw there is. You can then calculate (generally) the time it will take to drain your battery. From there you'll want to head to the fuse box and determine which circuit(s) is causing the draw. You'll know as the draw will be similar to that you found before. I'd also check the relays, first, as an easy step before unpluging and testing all the fused circuits. You can do that with the multi-meter as well.

I know a lot of guys won't tackle an electrical problem head-on like this, but if you're patient you will eventually figure it out. In the meantime, you can get a solar charger from Harbor Freight that plugs into the cigarette lighter, it will make up for voltage loss you currently have.

Good advice. I also just ordered a battery minder so I can always throw that on if I am parking it for a while. AZ said they will replace battery under warranty regardless of what their tester says. I am thinking it might be my fault though. I use my winch a lot, have an electric fan, and a 1700Watt Stereo. I upgraded to a 136 Amp Alternator a while back, but it seems that might not be enough since it usually screams a bit under full load.

tigerblood 07-25-2013 09:15 AM

What alternator do u have? Thinking of upgrading mine too

Redrider94 07-25-2013 09:20 AM

Is your amp controlled by the key? Or is it wired to the battery direct? Had a friend that wired his amp to the battery and also wired the control wire to the battery as well. Would drain the battery over night, in unhooked the control wire and ran to the fuse box so it would only work with the key no more problems.

OverkillYJ 07-25-2013 10:01 AM

Quote:

Originally Posted by Redrider94 (Post 4001353)
Is your amp controlled by the key? Or is it wired to the battery direct? Had a friend that wired his amp to the battery and also wired the control wire to the battery as well. Would drain the battery over night, in unhooked the control wire and ran to the fuse box so it would only work with the key no more problems.

Nah, Stereo is wired correctly. I have had that in there almost as long as I have had the Jeep. The control wire gets wired to the headunit so that the amps only turn on when you turn the stereo on. The 0 Gauge line for the amps goes directly to the battery, then a 2 farad cap, then out to the amps.

OverkillYJ 07-25-2013 10:03 AM

Quote:

Originally Posted by tigerblood (Post 4001339)
What alternator do u have? Thinking of upgrading mine too

If I remember right it is either a Dakota alternator, or a Grand Cherokee alternator. It is def one of those. They are very similar. I cant remember because I actually bought both. One did not fit and I returned it for the other. There are a lot of write up on it though. You have to bypass the fuse box when you do it. I ran a 2 Gauge wire to a waterproof circuit breaker on the firewall, then to the battery.

tigerblood 07-25-2013 10:08 AM

Cool. Thanks

bruceandjo95yj 07-25-2013 11:37 AM

Dont let your jeep set that long.....mine hates it....acts a fool if i leave it more than a day lol


All times are GMT -5. The time now is 05:49 AM.