"refilling" the battery - lost art?

[george graves]

I recently got a sealed "optima" type battery, and love it. It cranks my m30 over like there was an army of smurf's under my hood. Half a revloution and the m30 fires up...

But It struck me tonight when I was working with some highly concentrated HCl Acid (yea I do that kinda of mad scientist shit in my free time) of an "old timers trick" to make a battery new again.

I remembered that when I was young - my dad would always keep a "wine box" looking thing of murtaic acid around, and a "hydrometer"...

All of the sudden I fell like a shumuck for all the over prices, POS batterys I got from k-mart/walmart/nutmart....$80 bucks for something that lasts 3 years...

I bet this "technology" is way too old for 90% of the members here, but people use to do it. Anyone that pipes up and says that all car batters sold today are "sealed" I'm going to call you a noob and make fun of you for days...They are not....at least none I've owned, they all have a "top" to them....wedge something in there and it will pop off...

To make a "fix"/change" to a battery, you need what looks like a turkey baster, but it has calibrated "beads" in it that float or sink, they will tell you the "specific gravity" (remember chem class?) of the solution. then you simply adjust. THey use to sell it at any pepboys...autozone...what have you

Other wise a led acid battery is just that - led plates, and acid - it's the acid that gets weak - then you add more...

Anyone still do this old trick?????


...

[Car Addict]

I am proud to say that i do know of this and have done it on a couple of the vehicles in my family works amazingly. learned about it when i took my automotive courses. so ya you dont have to be old to know this just know about how car shit works is all.

[Farbin Kaiber]

I've done it a few times for broke customers at my shop that can't afford a new battery, the hydrometer is rather cheap, 20-40 bux and acid, well, hit up a local pool chem shop. I had one on my beater work van last almost three years after the five it had been in there.

[browntown]

I have a servicable battery from Napa, but the thing has a 7 year warranty on it, so it's easier to drag the 120$ lump into the store for a new one.

[AndrewBird]

Yup, known about it pretty much my whole life. We actually have a plastic container with a valve on it made to fill batteries.

You don't have to use acid to top it off though. You can just use water and the battery being charged will change the water into acid. It's a good idea to use distilled water as minerals in the water will supposedly hurt the battery.

You want to fill it until the "cat eye" goes away at the bottom of the tube. Basically the fill holes are a tube with a slot cut in them, but only partway up. You want to fill up to the top of these cuts. It will make sense if you look. Generally there are 3 tubes per cap, but there could be more/less.

On a side note about distilled water, we have been using tap water to fill batteries and radiators here for all my life with no ill effects, but then again, the tap water here was recently rated best in the state and I think 3rd best in the country, so...

[Jscotty]

In a throw-away society, this has indeed become a lost art. The first time I tried this, I was 16 and I spilled a little bit of the acid on my pants. I expected it to burn me but it didn't. The next day there were 2 big holes in the knees where the acid spilled on me! LOL

I was too cheap to get a hydrometer so for me, this process was trial and error.

[LINUS]

I work in an acid plant making the acid, so please spill plenty when you work, I need job security.

It's a super weak solution, just get it off your skin within a minute of contact & it won't leave a mark. The 'acid burn' of stronger acid is the acid pulling the moisture out of your skin, for all those that like those sort of facts.

[Jscotty]

Interesting. My chemistry teacher used to tell us to always add HCL acid to water rather than the other way around. Or at least if you did, it would cause an explosion. Would it be an explosion with impact or would it be just a big splash or what is the real deal behind this principle?

[george graves]

The thing to remember is "do as you ought-to, add acid to wat-er" Best rimes with a boston accent.

Adding water to acid cause a exothermic reaction, if the concentration is high enough.

[LINUS]

The thing to remember is "do as you ought-to, add acid to wat-er" Best rimes with a boston accent.

Adding water to acid cause a exothermic reaction, if the concentration is high enough.

That's the text book version. The dumb knuckle-dragger reason is a little water in a lot of acid causes a weird boil reaction that can "pop" as it boils and splatter acid, also like George mentioned the heat is so great it can warp a vessel, or at least damage it.

Obscure fact : weak solutions are more corrosive than strong, also the freezeing point (more like umpump-able sludging) point of strong sulfuric acid is just under 50* F. So you have to heat trace all lines in WA state & keep the heat on almost every night of the year.

[Mastrcruse]

We actually had to do this with the '61 vette this weekend to get it ready for the dream cruise. Its a battery that was made to look like an old tar top and we had to unscrew and fill

[AndrewBird]

Here is a pretty decent article on the subject:

http://www.justbajan.com/cars/maintain/052501-01/printer.htm

[2Big4a3Series]

I know that this is an old thread but I was wondering if changing the acid on battery will bring it back to life?

I bought a new battery 18 months ago but it sat on the shelf the whole time and of course, it went dead. I discovered that it will not hold a charge and I was wondering if changing the acid will help?

I suspected that battery acid neutralizes over time and I tested this by dumping out some of the fluid into a 5-gallon bucket and pouring baking soda on it. I got no reaction. I did the same test using the new bottle of sulfuric acid that I picked up at the auto parts store and I got the bubbling and fizzing so it confirmed what I originally thought.

BUT I am not foolish enough to think that I have this all figured out. Would "fixing" my battery be as simply as dumping all of the water out and refilling it completely with the new acid or do I have to add water with the new acid?

Also, I'd have to be wise enough to ask:

1. Is this even a good idea?
2. Are there any immediate dangers that I should be concerned about?
3. Should I trickle/slow charge the battery after refilling it or can I do a standard charge with the 100 amp automotive charging machine?
4. If I bought chemicals from a swimming pool shop (as Farbin suggested) what would I ask for?

[archemedes]

slow charge is best

[Zyth01]

I recently got a sealed "optima" type battery

If I remember correctly, the Optima (Autozone) and the Orbital (Checker, Schucks, Kragen) aren't traditional acid filled batteries, that's why you can mount them sideways, upside down etc.