What can be draining a battery?

[BlueOvalStangGT]

What I thought was a dead battery wasnt. We were changing rims on my freinds accord and we needed tools so I went to my car and popped my trunk and my trunk light didnt come on. Then I checked the rest of my car and sure enough the battery was drained again. What could this be? Its a brand new battery with brand new terminals. When the car is running the battery voltage guauge reads normal so its gettign a charge. What accesorys that I have can be draining it? All I can think of that I have wired is my wideband o2 sensor, my radar detector, my gauges and thats it. What cuases a battery to drain?

 

[94gts]

What cuases a battery to drain?

a bad ground somewhere

 

[super302]

Typically it is something draining the battery. Small things like glove box or courtesy lights are often the culprits. If you have an aftermarket stereo or alarm system, it is also suspect.

The ideal method is to disconnect the positive terminal, and connect a Digital Multimeter (DVM) between the positive terminal on the battery and the positive cable. Set the DVM on a low current scale of 2-5 amps if it doesn't auto range. Watch the current draw, and then start pulling out fuses. When you see a sudden drop in the current, that circuit is the likely culprit. Note that the computer, radio & clock will draw less than 1/10 amp to keep the settings alive.

See http://assets.fluke.com/appnotes/au...ve/beatbook.pdf. You will need the Adobe Acrobat viewer which is also a free download – http://www.adobe.com/products/acrobat/readstep2.html

 

[HISSIN50]

Patrick, that sounds like JRichker.....

 

[super302]

Patrick, that sounds like JRichker.....

maybe it is....maybe it isn't

 

[TripleBlack95]

I just replaced my battery as well - HOLY CRAP was my Vert not getting any power because of it.

My question is - how the HELL does my body shop return my car to me (a few weeks ago) with my battery DEAD, saying it needed to be jumped, and barely cranking? Are they that incompetent to make sure the lights are off and the doors are fully shut? WTF?!

 

[BlueOvalStangGT]

Super, Im not good with DMM so could you help me out, heres what mine looks like, what setting should it be on?

 

[mo_dingo]

Super, Im not good with DMM so could you help me out, heres what mine looks like, what setting should it be on?

See where it says DCmA, that refers to milliamps of DC current. and the highest setting it has is 200ma, which is .2 amps. That meter is useless for you.

You need one like sears sells, that had a amp clamp, and can read both DC and AC amps. It's 50 bucks and works awesome. I use it at work all the time.

Another way to try it is get a DMM that has a amp rating of at least 20 amps DC. That way you can probe all of the fuses and see where your amp draw is going.

Have you even verified that the car is drawing any amps all the time? You need to do so, and the amp clamp is the best way to do it.
Scott

 

[mo_dingo]

oh, and if you get a regular DMM with test leads, without the amp clamp, put it on the 20 amp setting, and disconnect the neg or ground, and attach one lead to the cable, and one lead to the battery which you took it off from. That way, the current that is flowing through the wire will have to flow through the meter, and it will give a reading.

I guessed you didn't know how to do an amp reading. Any time you do, remember, the current that flows through any positive wire will have to flow through the negative wire as well. So it doesn't matter which cable you disconnect at the battery, as long as the current has to flow through the meter to reach the battery, the DMM will be able to take a reading. And this goes for any other thing you are testing. Usually I use the positive wire though.
Scott

 

[BlueOvalStangGT]

Another way to try it is get a DMM that has a amp rating of at least 20 amps DC. That way you can probe all of the fuses and see where your amp draw is going.

Have you even verified that the car is drawing any amps all the time? You need to do so, and the amp clamp is the best way to do it.
Scott

So either way I need a new DMM? Paying for college is taking a huge toll on my bank account, do you have a part number on a multimeter I should look into? Maybe I can find one cheaper online or something.

 

[BlueOvalStangGT]

Bump

 

[mo_dingo]

So either way I need a new DMM? Paying for college is taking a huge toll on my bank account, do you have a part number on a multimeter I should look into? Maybe I can find one cheaper online or something.

You simply need a DMM that can read at least 20 amps. More is preferable, but they are usually more expensive.

The other route is to get one of the ones I have (I have 3), and that is the craftsman one. Check this link out.

http://www.sears.com/sr/javasr/product.do?BV_UseBVCookie=Yes&vertical=TOOL&pid=03482062000

If that link doesn't work, the sears part number is 03482062000

It's $49.99, and it reads up to 400amps on both DC and ac with the amp clamp. It's awesome for what I do, and will work great for your application.

Using a regular DMM w/ the test leads to measure amps rarely works without a seriously expensive meter. Some go up to $400.

Anyway, that one works great. I would recommend only using it for amp readings. Leave the high voltage AC for a cheap meter.
Scott

 

[BPA]

I like my fluke 88 very good meter but pricey if ur not using it much..