Educate me on battery acid

[TnAndy]

I guess here as good a place as any to post this.

About 12-15 years back, I bought a battery from a local place for my previous tractor. They got them in dry, and added the acid to them there. I asked about buying one dry with acid separate, guy said sure, I'll sell it that way. So I bought the additional one, and a 'box' (plastic bag inside) of acid.

Year or so ago, I notice the 'box' was leaking acid, not much, but it told me the bag was breaking down, so I poured the acid into a couple of gallon glass jugs. It came out to 1 and 1/2 gallons. Might have lost a few ounces, if that, to the leak, it wasn't much.

So now I could use the battery, and have the following questions I can't ask the place I bought it since they have closed and gone. (Yes...I realize that would have been prudent to find out in advance.... )

1. Looks like WAY more liquid in the 1 1/2 gallons than that size battery could hold (but maybe it isn't).


2. How I would know if the acid is the proper strength to pour directly in the battery, or does it need to be diluted with water to some point. I assume I can use a hygrometer (?) or something to test what is in the jug, and what reading should it be to go in the battery.


Thanks !

 

[Billrog]

Just put the acid in the battery and add water if necessary. That's all there is to it.

 

[TnAndy]

So you're saying the liquid I have is the proper ratio of acid/water ?

Pretty sure that gallon & half will more than fill the battery give the size it is.

Additional question: Will the battery have to be charged after filling ? I have a charger that will do 2amp/10amp/50amp. What setting to use IF it does need charging after filling ?

 

[2LaneCruzer]

Sulfuric acid is fickle. Adding water to concentrated sulfuric acid can cause an exothermic reaction that is basically an explosion, that will blow acid and water everywhere. It gets REALLY hot. In the lab, we were taught to pour the acid into the water, instead of the other way around. Sulfuric can, and will blind you and burn you before you can get it off. Don't get it on you, and especially don't get it in your eyes.

 

[TnAndy]

Sulfuric acid is fickle. Adding water to concentrated sulfuric acid can cause an exothermic reaction that is basically an explosion, that will blow acid and water everywhere. It gets REALLY hot. In the lab, we were taught to pour the acid into the water, instead of the other way around. Sulfuric can, and will blind you and burn you before you can get it off. Don't get it on you, and especially don't get it in your eyes.

Yeah I remember high school chemistry....acid into water, not water into acid.

 

[LouNY]

Battery acid as delivered in the container is ready to use, don't dilute it.
Fill your battery to the proper level.
You should take a few precautions while handling the acid,
it will burn you and eat clothes and flesh for that mater.
Pour carefully rinse will anything that it gets spilled on.
The battery should be ready to use after filling it.
Usually charging is not required prior to use.

 

[TnAndy]

Thank you sir !

 

[KennyG]

The battery acid you were given should already be diluted to the proper concentration. Fill the battery to the marked full level. Battery acid is about 30% sulfuric acid, if I recall. Clearly dangerous and should be handled with care, but not high enough concentration to cause a reaction if water is added. You may have more acid than you need because it was a standard package and has enough for the largest batteries.

After the acid is added, the battery will have a charge. However, I would probably give it a slow charge for several hours. If your battery charger has an automatic setting that will monitor the battery and taper the charge, that would be ideal.

Your next question would be how to dispose of any leftover acid. (Once the battery is filled, you never add more acid, only water.) The leftover acid can be diluted and put down the drain. Even though your acid is already diluted, dilute if further by pouring a small amount of acid into a large amount of water. (No matter what the concentration never pour water into acid.) Eye protection and rubber gloves are recommended when doing anything with acid.

 

[RNeumann]

OTC 4619 Professional Battery Hydrometer https://www.amazon.com/dp/B0050SFVHO/ref=cm_sw_r_cp_api_i_.1oxCb94Z0QG8

This old school but since you are in that mode......

 

[Tractor Seabee]

If I remember right a hydrometer measurement varies with the state of charge. As the battery discharges the specific gravity of the acid drops. It then rises until fully charged. In the early days of lead acid batteries they were tested with a hydrometer and compared on a chart to determine level of charge. Not possible with sealed batteries. The acid concentration varies by manufacturer and type. Acid maintained in a airtight container that is matched to the battery should be OK. If the water fraction has evaporated and concentrated you can ruin your battery. To be safe you need to know the original specific gravity of the acid. From your story of the leaking container I would suspicion that the breakdown of the plastic and the leaking has changed the acid concentration somewhat and added impurities from the action on the plastic. Don' be surprised if things do not come out good. You may luck out, worth trying. LOL

Ron

 

[paulfun9]

Don’t dilute the acid at all. Slowly pour it in then let battery have a slow charge with the trickle charger for a few hours.

Take the wife’s baking powder and use it to neutralize any spilled acid or wash your hands with if you do spill any. It will neutralize the acid and help greatly containing any damage the acid comes in contact with.

 

[Larry Caldwell]

The battery was shipped dry charged. When you add the acid it will probably come up to about 80% charge, but let it sit for an hour or so to completely wet the plates. Then give it a slow charge to top it off, and check the level of the electrolyte. Dry charged is the only way to store lead-acid batteries for any length of time.

 

[jaydee325]

Flooded cell lead acid battery electrolyte is typically 35% sulfuric acid and 65% water solution. Use it as is to fill a new dry battery.

For maximum life, the battery needs to be charged prior to putting it in service. Fill the battery, let it sit for at least an hour to allow the electrolyte to be absorbed into the plates. Then, optimally, use a smart charger to get a full charge (at least 14.4 volts). Let the battery rest and check voltage again, if less than 12.7 volts, put it back on the charger until you get 12.7 volts after the battery is rested.

I know lots of people just fill and use, but if you want maximum life, make sure the all important first charge is performed correctly.

Battery Basics - Guide to Batteries | BatteryStuff

 

[CobyRupert]

When one gets into it, there's always talk about measuring the specific gravity of the acid using those bulbous "turkey baster" hydrometer testers like for anti-freeze.
And there's charts that's say specific gravity (S.G.) shows how charged the cell is:

100% Charge = 1.265 S.G. = 12.7V
75% Charge = 1.225 S.G. = 12.4 V
50% Charge = 1.190 S.G. = 12.2 V
25% Charge = 1.155 S.G. = 12.0 V
Discharged = 1.120 S.G. = 11.9 V

I don't understand what is the point of measuring S.G.:
1) Why measure specific gravity and not just use a voltmeter? The only scenario I can think of is maybe you can tell which cell (of 6) is a bad cell if that cell's S.G. is lower than the others. But, again: So what? It's not like you can fix one cell. So what does it tell that a voltmeter doesn't?

2) How can charts say, for example: "100% Charge = 1.265 S.G. = 12.7V". Aren't you measuring only one cell. So wouldn't 1.265 S.G. =12.7v/6 = 2.117 Volts?
[So if 5 cells are 1.265 S.G (2.117V) and the 6th is 1.155 S.G. (2.0 Volts) then would the voltage be 12.59V (=(5 x2.117v)+1.155v)?

 

[LittleBill21]

sg is used to show when a battery is full. led acid battery's actually need to be overcharged to get SG levels up or the battery becomes sulfated. so the voltage will be high, yet the minute a load is placed it will have no capacity

you keep charging at high voltages +15v until sg does not climb, that indicates the battery is actually full. voltage won't show this.

 

[Tractor Seabee]

Little Bill is correct

Acid solution S.G. of an operating lead acid battery is totally dependent on the % solution of the original electrolyte. The manufacturer is the only source of that information as they select the solution on the basis of plate composition and other factors. Automotive batteries are probably all within a narrow S,G. band so Cody's chart is also probably close enough. S.G. is only accurate if the battery is topped off w/water to the full level. The aspiration of the hydrogen gas causes the electrolyte to become more concentrated. Operating a battery short on water will shorten the life greatly.

I have been involved in installing industrial battery banks for large power supplies. They come dry charged with the electrolyte separate. The manufacturer provides all the info and an S.G. chart for those specific cells.

There is a lot of science to lead acid batteries that is not too important to the average user. Keep the electrolyte topped off w/water and replace when it dies.

Ron

 

[CobyRupert]

sg is used to show when a battery is full. led acid battery's actually need to be overcharged to get SG levels up or the battery becomes sulfated. so the voltage will be high, yet the minute a load is placed it will have no capacity

you keep charging at high voltages +15v until sg does not climb, that indicates the battery is actually full. voltage won't show this.

By "full", I assume you mean fully charged (i.e.amount of electrons (coulombs)) available? As opposed to liquid level or voltage level?

For years, I would always top off batteries year to year with distilled water. Lately I top off with battery acid that I buy at auto parts store. Which is correct? Or should they be mixed etc...?

 

[KennyG]

For years, I would always top off batteries year to year with distilled water. Lately I top off with battery acid that I buy at auto parts store. Which is correct? Or should they be mixed etc...?

I think this is a mistake. When a battery heats up and "boils", only water is lost. The sulfuric acid stays. If you add more acid, you will be increasing the acid concentration. I'm not sure how long before this is a problem, but theoretically you could get into a situation where adding more fluid would cause a reaction.

 

[Tractor Seabee]

I think this is a mistake. When a battery heats up and "boils", only water is lost. The sulfuric acid stays. If you add more acid, you will be increasing the acid concentration. I'm not sure how long before this is a problem, but theoretically you could get into a situation where adding more fluid would cause a reaction.

Water is also lost from solution due to the aspiration of hydrogen and oxygen created by the charging process which breaks down the water to its component elements.

Ron

 

[CobyRupert]

I think this is a mistake. When a battery heats up and "boils", only water is lost. The sulfuric acid stays. If you add more acid, you will be increasing the acid concentration. I'm not sure how long before this is a problem, but theoretically you could get into a situation where adding more fluid would cause a reaction.

....but I thought acid levels also decrease (i.e. acid is "lost" from solution) over time as it turns to lead sulfate on the plates or precipitates to the bottom of battery (before it eventually builds up and shorts plates/battery death.) That's why I thought maybe replacing acid (and water) is the way to go. No?