2nd Boiling Battery - Input needed (2 Viewers)

[EasternYeti]

So I’m driving home tonight and I had my roof rack LED bar on for a few minutes as I went through some curvy roads and I started smelling Sulfer, pulled over and the battery was fuming.

Some back story, at the SAS this year my 8 year old auxiliary optima met the same fate, but I wasn’t using lights at the time and attributed it to a old battery. However, This time around the battery is top of the line and less than five months old.

My rig has a dual battery system with a battery isolator. Should I look at that first as the culprit? None of the fuses blew - from the lights or anywhere else - which leads me to the only non-fused link....the isolator.

What I don’t understand is that If the isolator is bad why didn’t my autozone special starting battery boil as well? Wouldn’t both battery’s get overcharged?

Where does the witch hunt begin?

 

[MANUCHAO]

How much charge is coming out from your alternator as you drive?
Could of been a bad cell in the battery (rare, but possible)

 

[TRAIL TAILOR]

I'd check alternator output and the voltage regulator.

J

 

[Seth S]

+1 on Voltage regulator. Sounds like it’s over charging.

 

[BlackCat]

Another vote for overcharging too. Sometimes you have to take all the fancy equipment out of the equation like battery isolators and fancy fuse panels and go back to the basics.

 

[Mr Cimarron]

Check the ground on the alternator. I boiled two batteries from the ground wire snapping resulting in overcharge.

 

[John McVicker]

James, send me your email (via PM is ok).

I ran your problem by my buddy that you met @ the Brewery in Moab. He thinks it could very well be your isolator. I will hook you 2 up so you can discuss in more detail. That way there won't be anything lost in the translation if I try to pass along his thoughts.

 

[EasternYeti]

James, send me your email (via PM is ok).

I ran your problem by my buddy that you met @ the Brewery in Moab. He thinks it could very well your isolator. I will hook you 2 up so you can discuss in more detail. That way there won't be anything lost in the translation if I try to pass along his thoughts.

Will do, bit of an update, I had the alternator tested today and everything checked out. diodes “passed” and so did the voltage regulator, but this was with a generic autozone tester that attaches to the battery

I’m thinking I’m going to instal the new auxiliary battery and test from there instead of the main battery

@BlackCat id love to get rid of the apparatus but with the dual batteries it’s a necessary evil

 

[BlackCat]

Will do, bit of an update, I had the alternator tested today and everything checked out. diodes “passed” and so did the voltage regulator, but this was with a generic autozone tester that attaches to the battery

I’m thinking I’m going to instal the new auxiliary battery and test from there instead of the main battery

@BlackCat id love to get rid of the apparatus but with the dual batteries it’s a necessary evil

Oh I mean I get you need to have them, I just meant as far as diagnosing goes. Not actually removing them from the vehicle, unless you isolate the issue to it.

 

[OSS]

Only way to boil out a battery like that is to apply an over voltage. Since the other battery wasn't fuming- the suspect looks like it's the isolator.

Wash down everything in the engine bay with baking soda & water. That acid mist has coated everything and rust will accelerate like nobody's business. Also it destroys the paint.

 

[lovetoski]

Boiling battery is a symptom of over-charging. Before replacing anything, I'd do some more sluthing.

Put a multi-meter on the alternator and run the truck at 2000 rpm (where you'll see the full amp output from the alternator). Then add loads and watch the voltage. If everything appears normal, then move the multi-meter to the primary battery and repeat. Then the secondary battery and repeat.

Super curious what you find out, please post back with results.

 

[Seth S]

Wire an aftermarket volt meter to the battery so you can watch the actual voltage from the drivers seat. Recommend digital for ease of numbers. V going above 14.6 or sitting at 14.+ with no load is a sure sign

 

[Tapage]

If the overvoltage ( V dash light ) ain't popping .. does not seems to be that.. I'm not saying that Mr. T dash indicators are the most reliable stuff .. but usually that battery part works ..

 

[dogfishlake]

When I bought my 100 it had the battery light on the dash and was putting out 16.5 volts and cooking like crazy. It even welded the ground to the battery post. Anyway, just sayin overcharging is crazy.

Carry on. Very interesting

And good luck!

 

[Seth S]

If the overvoltage ( V dash light ) ain't popping .. does not seems to be that.. I'm not saying that Mr. T dash indicators are the most reliable stuff .. but usually that battery part works ..

?
“V” dash light? You referring to the battery light that lights with key on. It goes out once the alternator starts charging?

 

[Tapage]

?
“V” dash light? You referring to the battery light that lights with key on. It goes out once the alternator starts charging?

yes that one .. if your alt it's overcharging and it's working properly that should come on ..

 

[60Works]

Weird that it didn't cook the spare battery. What isolator are you using?

 

[FJ60Cam]

What is the charging voltage it's putting out? This is a GM swap, right?

If the wrong wire is used as the sense wire, it will put out massive voltage.

 

[Seth S]

?
“V” dash light? You referring to the battery light that lights with key on. It goes out once the alternator starts charging?

Interesting. I’ve never heard of that light turning on for overcharging. I thought the alternator had to stop charging so that the voltage disappeared from the other end of the circuit allowing current to flow through that light to ground and hence light the light.

 

[EasternYeti]

OK so a few updates -

From the Alternator to the Isolator it was pulling 15.6 Volts, on the studs where the battery cables were connected the auxiliary was also reading in the 15.6 range, and on the primary, it read 14.85. This is curious given that I always thought this charge would be consistent across both terminals on the Isolator? Correct me if I'm mistaken

In my attempt to troubleshoot I disconnected the Auxillary battery from the Isolator, and when I tested the Primary battery (the only remaining link on the isolator) Terminal Dropped to 12.7 volts.

So what I did was remove the isolator altogether - linking the Alternator straight to the main battery and I'm running right around 14.9 Volts as tested with a multimeter.

My reasoning is this, all of the times I've had issues similar to this the truck has been under load, If I drive around for the week as I normally do the same circumstances will appear, and if I don't burn another battery to the ground I know the alternator & Voltage regular within is safe and the isolator is the culprit. If it does burn another battery ill get it warrantied again and buy a new isolator.

As this issue is irregular this is the only way I think I can narrow it down to a faulty voltage regular or the isolator. This Isolator is literally the last "original" element that the previous owner installed, and it's likely going to get replaced anyway.

In regards to that, it would be SUPER appreciated if anyone running dual batteries here can add a link to the specific battery isolator they use? I don't know where to begin with looking for a replacement. Mine is fairly simple with 4 studs so a baboon could do it. I looked a few blue sea isolators but I'm not sure which is the right choice