hi sl6 sages- not sure who to direct these questions to so i put them up on the board. ive been trying to charge a 12v lead acid battery from exide which appears to only be 1 year old and came in a sl6 vehicle i recently bought. after a 24 hr trickle charge, it shows 10 1/2 volts. cells are full. all the cells i then checked with a specific gravity hydrometer. each cell except one shows a sg in the fully charged range. the one exception shows an sg in the discharged range ;apparently that cell wont accept the charge. am i correct to conclude that that cells plates are damaged or sulfated between the plates and thus shorted. exide is a good brand and it is a 72 monther. this battery is probably a goner but i know it once worked. if i am correct in my suspicion that the one cell sulfated and shorted out, isnt that very unusual in one year? 2d question: most sl6 vehicles have and call for top terminal batteries. these batteries tend to load up with that white corrosion on the terminals which causes starting problems if you dont stay on top of maintenance. all cars now seem to have these side terminal batteries which corrode a lot less if at all. i think this is because the hydrogen gas produced during the charging process corrodes the top terminals which are near and slightly above the cells, hydrogen gas being lighter than air and rising. figure that the side terminal batteries avoid most of this problem because the gas doesnt get to them. am i correct and is this why the side terminal models replaced the top terminal models? if so when its time to replace a battery in our sl6 relics should we go to side terminals by replacing the cable ends on the battery cables or just get those screw in round male terminals for the side terminals on the battery? never saw this dealt with before in the forum . appreciate you letting me know if my observations are correct. thanks bob fisher

Sulphation is only one of several mechanisms by which a lead-acid battery's cells can die. Perhaps your dead cell sulphated, or perhaps some other fault developed. Whatever, it's dead. If you have the receipt for it, swap it in on warranty. If not, go get a new battery.

Side-terminal batteries were GM's dumb idea for 1972. No other automaker has used side-terminal batteries, only GM. They are not better! You just trade a hassle that's easy to deal with (corrosion can easily be prevented on top-terminal batteries) with a set of hassles that's much harder to deal with (difficult to get jumper cables to clamp onto side terminals, terminal bolts corrode and/or seize, side terminals pull out of the battery case, etc.)

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Nobody sweats the details like GM, and they don't!!!

Bob,

Good work with the hydrometer. Sorry you have a bad battery. Side terminal batteries stink for all the reasons Dan listed. Also, don't change just the ends of your battery cables. If you have a bad cable get a new one. You can make up good battery cables, but not with clamp on lead terminals.

Hydrogen is not corrosive. Terminal corrosion is typically due to an imperfect seal at the post. Avoiding mechanical stress on the posts and sealing the terminals works well for my batteries.

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Joshua

thanks joshie, dan and a100- useful answers you have given me, but incomplete. so the hydrogen gassing from the cells on a top terminals is not a factor in the whiter corrosion buildup??? having fooled with many batteries there really is much less corroding on the side terminal batteries. would seem if the main cause of corrosion is imperfect sealing at the terminal post(presumably acid/fumes leaking out?) then you would have the same corrosion with side terminals unless they are sealed better which i doubt. i agree a big disadvantage of the side terminals is difficulty using jumper cables which tend to pop off them. basically thought a dead cell was either sulphation or damage to or bending of a lead plate leading to a short. what else could cause a bad cell? have seen pictures of a batterys internals but never took one apart. thanks sages for keeping up with my questions. does look like curtains for this battery. anybody ever turn one over to drain it out (in a container of course) , then open the case and clean/straighten out the lead plates in a cell? thanks again bob fisher

I wouldn't even consider trying that. I wouild try to find am Exide dealer, and get the battery warrenteed. All batteries have a date code on them. The dealer will go by this code, when the reciept is not available. That battery might even be in the "free" replacement part of the warrente.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

I understand wanting to satisfy your curiosity, but sometimes (and this is one of those times) your quickest and easiest way forward is just to chalk it up to the SH principle (Stuff Happens) and move on. Sulphation, mechanical open or short, internal connector failure, space aliens' early April Fools prank...for whatever which reason, you've got a dead cell!

By default, if you take no other measures other than connecting the cable to the battery, the side terminal cable terminal-to-battery terminal junction is better sealed than the top terminal junction...but that is the only advantage, and it is easily nullified by using good practices when connecting the cables to top terminal batteries. If side terminal batteries were really and truly better, the auto industry would've adopted them sometime over the last thirty-six years, and that has not happened — it's only ever been a GM thing.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

thanks dan for the benefit ofyour experience. what would be the best way in your opinion to stop the corrosion at the terminals. the ways i have seen and used: uncle moe used to swear(should have heard the adjectives he used when i thought of draining and opening the battery) by putting a light coating of vaseline on the posts and cable ends. never thought that was very effective. have used these felt green and red rings on the post under the cable end. didtnt find them overwhelmingly effective either. only other thing i tried which did a moderately fair but not perfect job was that battery terminal blue spray from permatex. never thought of better sealing of the posts to the battery top. how would you do that- light coating of a epoxy(jb weld)? again thanks tons, getting areal education here. bob fisher

The main #1 thing is to avoid mechanical stress on the top posts. make sure the cables are the correct length and are routed and secured correctly so that they can't and don't apply sideways force to the terminal posts.

The felt washers are worth using as part of the strategy.

If you want to try to seal the connections, you can spray rubberised undercoating on them...but really, now that you've solved the overcharging problem, your battery won't be boiling and spitting acid at the terminals any more and you will find the corrosion problem mostly disappears on its own.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

One thing to note, as I ran through this 10 years ago when I used a set of Exide 1000's and 1100's for demo derby, after a few 'hits' the plates 'sluffed' off in a couple of the cells and would no longer charge or hold sufficient current to roll a big block over... the dealer tryed to make a 'stink' since the batteries were only a month or so old, even with the date code I had to produce a receipt for a 'warrantee' claim (fargin Icehole)... but got two new batteries after forking over the receipt...

FYI, I have had much better success with the optima battery at this point than the big exide's could hold up to...

-D.Idiot

Various factors cause short-circuited cells in lead acid batteries. In old batteries (most common), the conductive active material from the plates flakes off gradually over time from vibration and from electrical cycling til it builds up in the bottom of the battery high enough to short circuit the plates. Also, as the plates charge and discharge, the physical dimensional changes at the surface of the plates don't occur perfectly evenly. It's a statistical phenemon. So, the surface gets progressively rougher with usage until it can stress the insulating plates to the point of failure, or whiskers of active material can actually grow through pores in the insulators until it contacts the other plate, causing a short circuited cell. In newer batteries, it is usually deep-discharge of a battery not designed for that usage (also, freezing) which short-circuits a cell; plate volume increases with discharge, which can stress and break the insulators between the plates.

It was common decades ago (especially pre world war 2 era) to disassemble and repair batteries; replace insulators, plates, etc. In fact there were whole shops which had battery repair as their primary business. Today this business has completely disappeared except perhaps for some special large heavy duty types such as are used in telephone company central offices, etc. Entire books hundreds of pages long have been written on this subject & business; fascinating reading if you can find one (I have at least two...) (these books are over half a century old).

It is true that hydrogen gas is not corrosive; however, when tiny bubbles of gas generated in the battery reach the surface of the electrolyte, they burst, propelling into the air above the liquid level tiny droplets of sulfuric acid, some of which make their way out of the cell into the air. In fact the whole left front area of the car is pretty much enveloped in a dilute fog of microscopic corrosive sulfuric acid droplets, which is why the terminals, battery tray, left inner fender, left hood hinge attachment & mechanism, and left torsion bar tends to corrode faster than on the right side.

Replacement terminals can be reliable if you solder them onto the cable as well as use the clamp on bracket. A propane torch on low setting has enough heat to solder this.

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1964 Dart 225 1966 Valiant 225
1966 Dart 273 1966 Barracuda 273
1969 Dart 225
'64-170 engine '66-170 engine
(two) 198 crank/rod sets in custom-fitted wooden boxes

wooden motor scooter with hybrid-electric drive

anyone ever mix in some baking soda in wit some grease and use it as terminal coating... works well.
i have also seen those clamps that u fill wit lead pellets and heat it up liquid and jam the wire in there when liquid

Try Canby Oregon buddy, Johnson Controls has an assembly plant there and they are buying spent auto batteries at $5 a core (and there are at least 3 shops in Salem that are also buying cores for reconditioning (one right next to Salem's only speed shop...)

Just because the bread basket lost their shops doesn't mean it's that way all over...

-D.Idiot

Old batteries are the raw material for new batteries, thats why they want them back. Out here Interstate gives me $12.00 for car batteries and $18.00 for the big group 31 truck batteries that I turn back in above what I am already exchanging. Here on the outskirts of LA city there are small shops around that rebuild batteries, they even reuse the case bottoms on some. You can taste the acid from the sidewalk. But Like the "good old days" batteries, they are not even close to the performance of modern batteries.

Personally I need more reliable batteries, so I go with Interstate or just the Napa around the corner if I have to. The cost of a new battery in one of our company trucks is nothing compared to the cost a dead one causes. For my own cars it is pretty much the same, a missed day of work, my wife stuck somewhere or a screwed up day off is not worth it. You are going to have to buy a new battery anyway, why not make you life better by doing it on your own terms?

As far as the seal being better on a side terminal battery, it is, but not after it starts leaking. It can really screw up a nice clean car before you catch it. This can never happen with a normal battery. If you have to use one, fine, but if not, why would you? With a good sized top post you can always drop in just about any battery that is smaller in a jam and get back on the road.

I just use vaseline with or without the felt washers, which do help. It is important to clean the clamps and terminals first and put the vaseline on the posts and clamps before assembly, so it is inside the connection, not just on the outside after. Don't let the cables touch the case. I think Dan pointed it out already, a battery that gets really messy quickly is being overcharged or is near the end of it's life.

That's interesting, that some places are still reconditioning batteries, on the West coast. What they likely do is dump the acid, slice the plastic case near the top, remove the bottom, clean out the flaked off plate material, do something about the separator plates between the active plates, and reassemble by plastic-welding the case and refilling with decanted recycled electrolyte with sp. gravity corrected to 1.280. That'll work if the plates weren't too bad off to begin with. What core batteries are mainly good for is lead recycling; scrap lead is worth over a dollar a pound, I think. I keep seeing this picture in my mind which was on TV a few years ago; it showed a scrapyard in Asia with thousands of junk car batteries which had been shipped over from North America in container ships, and there were two barefooted Chinese women employees walking around the mess with sledgehammers, smashing the junk batteries to bits to separate out the raw materials...

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1964 Dart 225 1966 Valiant 225
1966 Dart 273 1966 Barracuda 273
1969 Dart 225
'64-170 engine '66-170 engine
(two) 198 crank/rod sets in custom-fitted wooden boxes

wooden motor scooter with hybrid-electric drive