Is there a tool to find a battery short?

dorlow · #1 02-20-2015, 04:03 PM

So, I just bought a battery about 2 months ago and I went to start my car a few days ago and it's dead. Won't even turn a light on or attempt to turn over. I attempted to charge it and my charger says the battery has an internal short and can't be charged. Now I know how to find a short the long way of using a multimeter and pulling fuses. It's time consuming. Hopefully I'll get to it this weekend.

But I work with a guy. He's a Systems Engineer and also a college professor so he's a pretty smart guy. I was talking to him about it. He says go to Autozone. They have a tool they can hook up that will tell you exactly where the short is. He says, but if you just ask for them to find the short, most likely they will just say they can't help you. But he's had them do it before. It's a big scanner that they have to roll out on wheels. They hook it up to your battery and with that tool, they can tell you exactly what component in your car is draining your battery. He brought his car in for it and they told him for free.

So, I called Autozone and asked if they could do it for me and obviously they told me they never heard of such a tool. Has anyone ever heard of this tool? Am I just asking for the wrong thing and if I gave the correct verbage, they would say "oh yeah, we have that... come on by" and I'd know where my short was in minutes?

aleekat · #2 02-20-2015, 06:06 PM

a 2 month old battery with an internal short should be replaced for free. you may have a battery drain issue. take it back where you bought it from.

Edit: an internal short in a battery is not the same as a short in the battery circuit.

dorlow · #3 02-20-2015, 08:44 PM

I understand an internal short is not the same as a short in the battery itself. I don't know if it's a bad battery or a short in the car. From my experience, a short in the car that drains a battery too low will ruin the battery. So, I don't want to replace my battery to just have it go a few months until the next time I don't have a need to drive my car for a week straight then ruin another battery from it not getting charged by the alternator for that long. It should be able to last months just parked and start back up.

777stickman · #4 02-20-2015, 09:01 PM

Disconnect the "neg" batt cable and hook in an "amp" meter. Then if you have a large draw, start pulling fuses to see what's causing it.

Tech II · #5 02-20-2015, 09:32 PM

There is no such tool......what it probably was a was a tester for the charging system or load tester for the battery....

Yes, a two month old battery should not short out.....probably isn't......it's probably just dead/sulphated......may need to do a slow trickle charge on the battery......

A fully charged battery should be about 12.65 volts.......check the voltage with the key in the crank position....need at least 9.7 volts to start.....

Get that battery recharged, car started, and check the charging system....if ok, either have a bad battery or a parasitic draw.....

la1 · #6 02-21-2015, 09:31 AM

I second what 777Stickman says. I was going to say the same. Harbor freight tools has an awesome battery diagnostic tool. you may want to get this tool to make sure your battery is actually up to par and the alternator is charging correctly. download the manual to see what the tool will do.

HTML Code:

http://www.harborfreight.com/digital-automotive-battery-analyzer-66892.html

http://www.harborfreight.com/digital...zer-66892.html

BTW I seriously doubt the battery shorted. if it did it probably would have exploded from all the hydrogen gas created when shorted. you are talking about 300-400+ amps dissipated in a few seconds

dorlow · #7 02-28-2015, 05:52 PM

Well, I think the short is fixed. I had my radio replaced. I asked the guy replacing my radio to look out for something that might cause it. When he took out my radio, he said my wiring harness looks like it was poked at numerous times and had bare spots. Also the factory amp was wired so it was on all the time (even when the car was off.) I don't understand how it worked great since brand new and 10 years later this came up. I had the first and only factory radio (under yesterday) installed days after I bought it brand new in 2004. They are the only ones that ever touched my radio (other than me.) A few years later, that after market radio died. I took apart the dash and removed the aftermarket radio and put back in the factory radio. All I had to do was remove the adapter that converted the factory harness to the aftermarket one. It was super simple. I didn't need to splice any wires. So, it only makes sense that wire would've been wired hot 100% of the time when they installed that radio. But why did it take 10 years to start getting dead batteries from the bad wiring?

dorlow · #8 02-28-2015, 05:54 PM

None the less, I checked the amps my car is pulling while off and it's now 7.91 mA. Before the new radio, it was 55 mA when off.

maxwedge · #9 02-28-2015, 07:32 PM

modern cars can pull at least 25ma when shut down.

dorlow · #10 02-28-2015, 08:01 PM

I mistyped my last post. I meant I had an after market radio installed days after buying the radio brand new. I then, myself, uninstalled the aftermarket radio about two years later when it broke and put in the factory radio just disconnecting the adapters. So this after market radio is the second one in the car...

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