WarrenW

Hi Everyone,

A few times driving I smelled something really wierd but wasn't the exhaust. Todat it did it again and I popped the hood and heard my battery boiling. The smell is the sulfuric acid!! Boy does that stink!

What can cause this? My friend and I put a voltage meter on the batter while running and not. Both times it registered 12V.

The battery is an Everstart showing 540 cranking amps / 450 cold cranking amps. Can the battery be too small? But what causes it to bubble after its already been cranked?

Thanks!!

Warren

snorulz

that usually means the car is over charging the battery. What is weird is it registers 12 volts though, charging will be around 14 volts. My guess is you have a bad voltage regulator.

Starfury

Sounds like it. If the voltage regulator is supplying a/c instead of d/c, it'll screw with the voltmeter readings and kill the battery in short order.

A bad battery can boil under normal charging conditions, but usually that means there's a dead cell. This doesn't sound like what's happening here.

First thing I'd do is take the battery and alternator in to get checked. If both are good, replace the regulator.

kalli

same opinion here. bubbling battery is usually caused by overcharging. i'm the same stumped that you only have 12V running ?!
anyway there's something odd in nyour electrical system has you should have ~13.5-14.5V running (not 12V). At the same time a bubbling battery might boil->explode. very messy and can be deadly serious when you're standing next to that.
I'd get that checked ot by a professional (someone who actually knows what he's doing) as that might be well dangerous

WarrenW

Thanks for the tips. I just went outside and the battery is dead now. I haven't smelled that until today and now its dead. I had the smell before but I had to get a new battery. But I don't know if I smelled it before or after the battery went out.

I thought the voltage regulators was built into the alternators? Is that on newer cars?

Thanks!

WarrenW

I just looked and I don't see my voltage regulator hooked up. thats why I was asking about the alternator if its built in. Is that the regulator in the first pic? I know the last guy put a brand new wiring harness in and he said its the latest version.

st66ng

I just replaced my regulator to solve my charging issues. It is located on the drivers side at the front of the car beside the radiator. Here is a pic of it, http://image.mustangmonthly.com/f/89..._regulator.jpg

You are right, newer alternators have the regulator built in, your mustang has an external one.

WarrenW

Thanks. I just looked and here is mine I assume. I drove the car much farther today than I normally do so over the time it must have built up and overcharged the battery too much.

WarrenW

I ordered a new regulator Friday and supposed to be here Monday. Can I pretty much eliminate that it can be the alternator? I mean, doesn't the voltage regulator control the voltage going back to the battery when its being charged?

I just want to make sure when I replace the regulator that it was the problem. My battery shows still around 12V when it was running but I did not rev the engin any. It was at a high idle though.

Thanks,

Warren

ThanksDad

It may be to late but if possible I would recommend an electronic regulator. They have no moving parts like the old ones. Mine has worked great for well over a year now and it solved my lights flickering problem.