Thread: Why do my batteries leak?

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I have a slammed 426 hemi-powered '96 dodge ram (actually its a bone stock 318 I can dream though...) and every battery I have ever put in that thing has leaked and corroded. One time the alternator and battery went at the same time (one took out the other), two other times I had a cell or cells go bad. So I am on battery #4 or #5 in ten years. Every one leaked. The system charges around 14.2 with the engine running. Other than the corrosion and short battery life, I dont see any other problems. Normal Bv is around 12-12.5 volts and load tests good (not excellent, but good)

I just went to remove the current battery to install in my car temporarily and noticed it seemed to be venting slightly as I was pouring water/baking soda over it to remove the corrosion. I'm sure the venting and corrosion go hand in hand.

Could this be a problem of cheap batteries or symptomatic of a problem with my truck?

Well, one thing you can do is cover the battery connections in grease if that is where you are getting a lot of your corrosion from. If the battery is boiling up through the top, (ie not a maintenance free battery) you could be overcharging it. When the truck is turned off after running for a while can you hear the battery bubbling?

Edit: Oh also, did this start after you replaced the OEM battery or did it do it as well? The reason I ask is that dis-similar metals are a big cause of corrosion and if the type of metal used on your battery posts is different than that of the battery cables/terminal lug that screws into the post, this will cause corrosion as well.

Cheers,
Dutch

At 14.2 the charging voltage is well within the proper range (13.6 to 14.4 volts) But with the engine at a higher rpm is it still within range? How full are you keeping the batteries? Should be able to look in the cells and see a 'split' or open groove up the area where the cap pushes in, the battery acid should be up to the bottom of the split leaving a 5/8th or 3/4 inch, or there about, space at the top of the battery for the acid to expand. The acid itself really dosen't expand, but with the bubbles created when charging, the acid can, and will get carried up and out the vent if it's to full. I can see one, or maybe two batteries being bad or questionable, but not a whole string of them. If it's an electrical problem, it's going to be one of those weird and simple things that you wonder why you didn't see it it sooner. Sorry, I'm out of ideas!

Originally Posted by Firechicken

Well, one thing you can do is cover the battery connections in grease if that is where you are getting a lot of your corrosion from. If the battery is boiling up through the top, (ie not a maintenance free battery) you could be overcharging it. When the truck is turned off after running for a while can you hear the battery bubbling?

Edit: Oh also, did this start after you replaced the OEM battery or did it do it as well? The reason I ask is that dis-similar metals are a big cause of corrosion and if the type of metal used on your battery posts is different than that of the battery cables/terminal lug that screws into the post, this will cause corrosion as well.

Cheers,
Dutch

Thanks for the response guys.

Dutch,
I tried the grease and it still comes through. Yes I can sometimes hear it bubbling when I shut it off. I wish I could remember whether or not the OEM battery did it. However I can say that I have been using the same replacement brand ever since. Posts (top mount) and clamps are both lead with the clamp bolt/nut which is steel. I dont think that is causing it though.
It's seeping over from out of the caps. I thought this was supposed to be a maintenance free battery (??). It says "NEVER ADD WATER" on top. What exactly makes one "maintenance free" ?

Sniper,
I have never had the caps off to look in (see maintenance free comment above). Charging voltage stays the same at higher rpm's... I agree on the bubbling but what could cause the bubbling and subsequent acid release if it's not overcharging???

Friend mentioned getting a "sealed" battery and ditching this one ??

Are you using a battery hold down to keep the battery from moving/vibrating? Have you used batteries from the same MANUFACTURER each time?

This problem is pretty common on the 74-78 Mustang IIs, and the main reason is that the battery is located in a high heat area. The factory even ran plastic ducting from the core support to the battery in an attempt to help wiht the problem.....which really didn;t do much good. The acids fumes would eventually take the paint off the underside of the hood over the battery.

The only real cure I have found is replacing the battery with an Optima battery.

I can't say what has been happening for the last ten years, but I am pretty sure I know why your battery is acting funky this time. Your MOPAR battery was ashamed about going into that chevy......... so it threw up.

It's either getting to hot from under the hood heat or overcharging...

Yeah if it's boiling out from under the caps, it's over-charging, over-heating or both. Shoulda' bought a Chevy....

yeah, have the alt load amp tested with a VAT 40 at an auto shop ( if you don't have 1 ), all that is needed is hooking up vat 40 pos and neg leads up to batt, then induction clip to the alt output wire, run engine, with lights and heater on, and make shure it's within spec there, should be 45 amps at most, for most vehicles. could then revv it up, see if it gets higher, then keep it about 2500 RPM and induce a load of the alt rating, to verify it is a good alt.

Originally Posted by Firechicken

Yeah if it's boiling out from under the caps, it's over-charging, over-heating or both. Shoulda' bought a Chevy....

I have a three chevy's.....and a ford too.

So if my charge rate is steady at 14.2 or so, do that not correlate to a steady charge current ?
Someone else mentioned the overheat thing, but it's winter time here (and most places). So that would mean overcharging but I am holding steady around 14.2 ??

Originally Posted by DennyW

...When you do a charging test, check the battery voltage before starting, then, when the engine starts, idle it up to 1500 or so, and hold it steady. The charge, and voltage rate should Decrease, and level off. If it stays at the higher rate, the battery is junk, or the voltage regulator is not working correctly...

I'll give that a try...thanks Denny.

Everbody seems to be on the same wavelength here. But we have to be missing something. I know this is hard to do if it's not a common, "natural" problem. Is it an induced problem? Have you added anything to the system that may be a cause to this? Remote start, battery isolator, big honkin stereo with a power booster? Shorted trailer wiring? Just throwing stuff out there, and seeing if it sticks! Had a cigarette lighter stuck in a customer car, ladies kids were fooling around with it, holding it in. Took out part of the wiring and the dash electrics wouldn't work all the time, that was a treat to find. Of course, nobody knew how that happened!! I still think your going to find something off beat and goofy when you do.

Sniper,
Nope, the thing is bone stock (save for my imaginary hemi). I changed the alternator (1x) and the battery several times. I did install a cassette deck at some point in time. Nothing special. It's wired into the factory connector so I could easily disconnect it. I'll disconnect it for giggles, clean the battery, get it tested (although my battery load tester says it's good...not a computerized one, analog with a toggle switch and two clamps), and stick it back in there and test out the charging system more in depth as Denny described.
Right now I am using it to troubleshoot the lights on my Biscayne....

I appreciate the help guys!

Well Poop! Another great train of thought out the window. Your just not going to make this easy are you!! "I just don't know." ( as I throw my hands in the air) Got to maul this over some more.