Educate me on battery acid

[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?