Mixing your own electrolyte from concentrated acid

[solarengineer]

I just drained an old deep cycle 12v as a test to clean the plates.

I drained the acid which had a small bit of black particulate in the bottom.

Then I washed the cells out with hot water from a 1/4" hose I shoved inside the cell

a whole bunch of very brittle pieces of black crap came out. I looks like small pieces of charcoal. Is this what sulphate looks like?

I flushed the battery until no more of this came out(about 20 times)

then I filled it with distilled and now its on a charger for 24 hrs as Nando recommended.

My question is, I have REAGENT grade (lab grade) concentrated sulfuric acid.

If I mixed this with distilled water, is this a proper electrolyte? I ask because I can buy lab grade sulfuric but not electrolyte..... go figure.

I read on the net that electrolyte is about 70% distilled and 30% sulfuric.

Does that sound right or is there a specific gravity that I need it to be?

Thanks

Jamie

[solarengineer]

I forgot to say also that I'm going to test a bunch of these pieces of charcoal looking chunk's to see if various readily available chemicals will dissolve it or not. Then I will try that in a battery and post the results

jamie

[Flux]

That muck is not sulphate, it's more likely to be bits of positive plate.

Unless those batteries have been out of service and left discharged they will not be sulphated. Traction type batteries used on a regular basis are charged fully after each discharge and there should be little reason to sulphate. Normal end of life failure will be worn out plates or corroded link bars.

I doubt that this changing the electrolyte is worth the trouble but you can try if the acid is cheap enough. Normally the acid is diluted to about 1.26 sg or a bit higher.

You will dilute it somewhat with the remaining distilled water but you can adjust after the first full charge .

Remember that concentrated acid is very nasty, treat with extreme care ( goggles, gloves). ADD ACID TO WATER, the process is highly exothermic and it will boil and spit if you add water to the acid.

Flux

[JW]

solarengineer/Jamie,

 If you plan to add water to ACS sulfuric acid make sure that you do it in a glass container, as it will get very -HOT- and boil somewhat.

 If you have reagent grade sulfuric, just test it with your battery hydrometer and go from there. If full state of charge is the specific gravity of the acid/electrolite you have, then don't add water. Make sure you have a known good battery(with a very full charge) to test the results against. Seems to me the reagent grade is not cut with water, when its addded to a new battery. For impeadence reasons maybe.

After mixing the water !(for godsake's wear safety glasses)! with reagent sulfuric, wait for it to cool before you put it in a battery, because it will melt your battery case.

JW

[willib]

Very good advice Flux

When i was in the chem lab i spilled some 1M HCl on the lab table , just a few drops , maybe a little more

and got some on my finger , didnt even realize till it started to sting.

Luckily i flushed it out ,in the lab sink as soon as i realized what i had done ,

i must have flushed it for fifteen mins at least,  all the while rubbing it .

also luckily no scar at all ,

i think if i hadnt washed it for as long as i did very bad things would have happened to my finger.

during flushing it was all white and spongy looking , my heart starts racing when i think about it ,

to the origional poster , be very , very carefull.

i was wearing goggles but gloves were not required

[richhagen]

Again to reiterate, add the concentrated acid slowly to the water.  -DO NOT ADD THE WATER TO THE ACID-  The reaction is exothermic - meaning it can get hot, and if you add water to concentrated sulfuric acid you will likely wind up wearing some as it will boil and splatter the solution around.  Hot acid reacts (burns skin or eyes) very rapidly.  Wear protective face shield and clothing if available.  Have fun - safely, Rich

[bob golding]

good job it wasnt hydroflouric. that would have meant instant amputation of said digit before it got to the bone marrow.