Adding water to a lead acid battery

[Tom in TN]

When I was younger the prevailing wisdom was to use only distilled water to top off a lead acid battery. Is that still the case? I just used a little bit of Evian ''purified'' water in one cell in my tractor's battery. What think you?

Tom in TN

 

[Matt in Oz]

Hi Tom

Deionised is the go so that you don't get other ions (charged molecules) interfering with the sulphuric / lead reaction. I have no idea about Evian water.

 

[wore out]

(quoted from post at 14:09:13 10/29/22) When I was younger the prevailing wisdom was to use only distilled water to top off a lead acid battery. Is that still the case? I just used a little bit of Evian ''purified'' water in one cell in my tractor's battery. What think you?

Tom in TN

From Evian dot com...

Mineral Composition in mg/L: Calcium: 80, Magnesium: 26, Potassium: 1, Silica: 15, Bicarbonates: 360, Sulfates: 12.6, Chlorides: 6.8, Neutrally balanced pH: 7.2. Dissolved solids at 180C: 309 ppm (mg/L). Evian has naturally occurring electrolytes contributing to the taste nature intended.

Even in small amounts I dunno why you'd want to dump all that in a battery???

 

[guido]

Tom in TN,

IT will survive! Old school was distilled water, rain water, tap water, in that order.

Any reasonably clean water will do.
A low cell,electrolyte below the plates, is a dead cell to be shortly if not already dead,

Guido

 

[Caryc]

(quoted from post at 14:09:13 10/29/22) When I was younger the prevailing wisdom was to use only distilled water to top off a lead acid battery. Is that still the case? I just used a little bit of Evian ''purified'' water in one cell in my tractor's battery. What think you?

Tom in TN

Why don't you just go to an Auto parts store and buy some electrolyte (battery acid)? I was once charging a 12 volt battery and the thing I had it sitting toppled over and the battery fell and spilled out most of it's contents. I just went to an Auto parts store and told them what happened and they sold me a container of battery acid for renewing batteries. It came with just enough to fill all the cells in a 12 volt battery. I got many more years out of that battery.

 

[JD Dave]

Distilled water would be my first choice.

 

[Caryc]

(quoted from post at 16:33:29 10/29/22) Distilled water would be my first choice.

Yeah, don't bother with the real stuff, just dilute it with water.

 

[Janicholson]

If the battery was tipped and electrolyte leaked out when it was charged, I would agree. If the level is just low, putting water in it does not dilute the strength at all. The charging and discharging the battery is subjected to separates hydrogen and oxygen from the water making venting necessary. The sulfuric acid component stays pretty much in the remaining liquid. Putting more acid in a non spilled battery is a bad idea. Jim

 

[Gene Davis (Ga.)]

Reccomended procedure from the golf cart battery service manuals: if the electrolyte is covering the top of the plates, charge the batteries first and when they are charged top off with distilled water after the batteries settle down from charging to 1/2 inch below filler neck of batteries.

If you fill them before charging the electrolyte will boil out of the top. If the plates are not covered, add just enough distilled water to cover them before charging and then fill them as listed above after the battery settles down from the charging.

We used this method for many years at the golf course where I worked and had very good service from the batteries there.
Gene Davis Tennille, Ga.

 

[Stephen Newell]

Today for the most part you don't service a battery. The reason they suggest distilled is the chemicals in tap water can change the PH of the acid in a battery. Purified doesn't necessarily mean free of the chemicals so I would stick with distilled.

 

[Steve@Advance]

A little bit one time won't hurt.

My concern would be why was one low, and how low was it?

If one was low enough that the plates were showing, and the others were still good, that could be an indication that cell was already going bad.

I would keep an eye on it, and if it does fail, don't blame yourself for adding a little water. It was probably already on the way out.

Also, how full are you keeping it? I have found trying to keep a battery with caps full to the rings will cause the top to stay wet and constantly need water, especially on an offroad application with lots of hard bouncing or vibration. They will tend to settle out to a happy level slightly below the rings, but still above the plates.

 

[Tom in TN]

Thanks for all of the replies. I guess to I need get some distilled water just to have on hand.

That one cell that was lower than the others was just down to the top of the plates. The other cells clearly had acid in them to above the plates so I didn't add any water to them. I'm going to keep a close eye on that one cell and get ready for a possible need of a new battery soon. That battery is almost three years old and seems to have plenty of power left in it spin the starter well, but I guess I'll see what happens as winter sets in.

Thanks again,

Tom in TN

 

[Caryc]

(quoted from post at 17:03:34 10/29/22) If the battery was tipped and electrolyte leaked out when it was charged, I would agree. If the level is just low, putting water in it does not dilute the strength at all. The charging and discharging the battery is subjected to separates hydrogen and oxygen from the water making venting necessary. The sulfuric acid component stays pretty much in the remaining liquid. Putting more acid in a non spilled battery is a bad idea. Jim

OK, so what do they fill the cells of a new battery with? Do they fill them partially then top off with water? If it's pure electrolyte that they use, why can't one top off a low cell with the same stuff? I don't get it.

I don't mean to argue about it. I just want to make sense of this.

This post was edited by Caryc on 10/29/2022 at 06:25 pm.

 

[Stephen Newell]

I think if a battery is tipped over and drains out it would be good to use fresh acid to fill it. If though the water evaporates out of a battery from being hot if you add acid you will
make the acid more concentrated than it should be. Water would be better to restore it.

 

[Steve@Advance]

When a battery loses electrolyte through evaporation and outgassing, only
the water leaves the battery, which increases the concentration of sulfuric
acid left behind.

Adding more electrolyte would further increase the concentration, so adding
distilled water would simply restore the concentration to where it
originally was.

If a battery were spilled or dumped, it would lose the acid solution, so in
that case it would need electrolyte instead of water.

 

[Caryc]

(quoted from post at 19:09:57 10/29/22) I think if a battery is tipped over and drains out it would be good to use fresh acid to fill it. If though the water evaporates out of a battery from being hot if you add acid you will
make the acid more concentrated than it should be. Water would be better to restore it.

No one has answered my question. What do they fill the cells with in a new battery at the factory? Do they add water to the electrolyte at the factory?

Is there any water in the cells when one buys a battery?

 

[Russ from MN]

I think your question was well answered! If you tip it over and loose the acid, add new, otherwise just add distilled water. An example, when I was young and inexperienced I hooked a 10 amp charger to a motorcycle battery and boiled it dry. I just added distilled water and charged it correctly with a small charger, it was fine for years.

 

[DoubleO7]

Yes, a new battery is filled with acid and water. Typically 60 to 70% water.

You can confirm this yourself by googling replacement battery acid, then viewing an MSDS data sheet.

They will list the ingredients as percentages of sulfuric acid and water.

Many years ago up into the 1970's many lead/acid batteries were shipped dry.
They would be filled with the electrolyte mix at thr retailer or distribution point.

Now a days, not so much if at all.

This post was edited by DoubleO7 on 10/30/2022 at 08:37 am.

 

[Caryc]

(quoted from post at 08:34:35 10/30/22) Yes, a new battery is filled with acid and water. Typically 60 to 70% water.

You can confirm this yourself by googling replacement battery acid, then viewing an MSDS data sheet.

They will list the ingredients as percentages of sulfuric acid and water.

Many years ago up into the 1970's many lead/acid batteries were shipped dry.
They would be filled with the electrolyte mix at thr retailer or distribution point.

Now a days, not so much if at all.

This post was edited by DoubleO7 on 10/30/2022 at 08:37 am.

Thank you, that's the answer I was looking for that was not given by any other poster.

 

[teddy52food]

So what happens if the acid gets a bit more concentrated? I have been adding acid rather than water.Maybe makes the battery stronger in the extreme cold?

 

[Janicholson]

The correct amount of Sulfuric acid in in the water when the battery is fully charged allows the difference between sponge lead in one plate to react with the lead sulfate in the other, creating electricity until both plates are nearly equal in sulfate. The remaining water is still acidic, but drastically less so. Excess sulfur in the water may make the transfer of sulfur back into the water more difficult when charging. Battery companies and their research scientists make the system just as ballanced as they can to get the maximum energy stored and out. The chemistry is still being tweaked with materials and physical arrangements, gels and fiber mats, and structural materials. Likely not going to make it better with higher concentrations of acid. jim

 

[Tony in SD]

I too have heard all kinds of answers to that question. So I ask my son, who is a chemistry, biology, physics and electronics professor at the University of Minnesota-Duluth (UMD). His undergrad is in Biochemistry/Molecular Biology, his phD has something to do with DNA that most of us, including me, dont understand. He said any water that is clean enough to drink will work just fine in a battery. Im going with that.

 

[Caryc]

(quoted from post at 15:41:16 10/30/22) I too have heard all kinds of answers to that question. So I ask my son, who is a chemistry, biology, physics and electronics professor at the University of Minnesota-Duluth (UMD). His undergrad is in Biochemistry/Molecular Biology, his phD has something to do with DNA that most of us, including me, dont understand. He said any water that is clean enough to drink will work just fine in a battery. Im going with that.

That all depends on what he means by clean. Water can look nice a clear and clean but have all kinds of dissolved solids and minerals in it. Try a TDS meter in it and see what you get.

 

[rustred]

exactly, but i am leary of water with high iron. always added well water.

 

[Caryc]

(quoted from post at 17:32:36 10/30/22) exactly, but i am leary of water with high iron. always added well water.

I have a well on my property, but I've been adding distilled water when needed. It's no trouble keeping a jug of distilled water in my storage shed. I can't even remember the last time I had to add water to a battery and I have three cars and two tractors.

 

[Tony in SD]

My boy said the percentage of chemicals in drinkable water is too low to have a significant impact on the batteries. If tha water is too bad to drink, that may be a different story.

 

[Geo-TH,In]

If you want to be real cheap, use water from a dehumidifier.
I use distilled water, it's cheap.

 

[560Dennis]

How low did electrolytes go ?


If electrolyte went below the cells the exposed air surfaces of cell are junk .

 

[Stuart]

That is incorrect. DI or distilled water is only to be used. Using hard tap water will dramatically shorten battery life. Try talking to the battery manufacturers.

 

[old]

WRONG saying all tap water is not to be used is like saying all cars are blue. All depends on the tap water and what mineral are in it. Some is just fine while others would not be good to use simple as that

 

[Caryc]

(quoted from post at 13:22:23 10/31/22) WRONG saying all tap water is not to be used is like saying all cars are blue. All depends on the tap water and what mineral are in it. Some is just fine while others would not be good to use simple as that

It's not like one has to arrange a bank loan to buy a jug of distilled water. :wink:

 

[Stuart]

Any tap water is usually hard water. You dont add tap water to batteries. Its common sense

 

[old]

Again WRONG tap water here where I am is hard water but in some places there is little to no mineral content to it. Plus you also have to figure in many homes have filters in there systems to that in turn filters out the minerals which is real common sense

 

[Stuart]

Again your wrong! But what do I know, I only maintain 125 forklift batteries in my dept made by east penn. they clearly state either DI OR DISTILLED WATER. Even soft water is not recommended.

 

[old]

Again as I said not all water is the same so some tap water is just fine but yes most places that is not true so distilled water is better in places with a high mineral content but that is not every place so you are in fact wrong to a point and like I said that is like calling all cars BLUE

 

[BarnyardEngineering]

(quoted from post at 18:24:07 10/29/22) OK, so what do they fill the cells of a new battery with? Do they fill them partially then top off with water? If it's pure electrolyte that they use, why can't one top off a low cell with the same stuff? I don't get it.

Water is a major component of the electrolyte, and is the part that evaporates off.

 

[Stephen Newell]

I've always been told the chlorine in tapwater will damage a battery. I'm sure some places the chlorine level is pretty low in tapwater but in my area the chlorine level is higher than what is recommended for public pool water.

 

[DoubleO7]

(quoted from post at 17:25:00 11/01/22) I've always been told the chlorine in tapwater will damage a battery. I'm sure some places the chlorine level is pretty low in tapwater but in my area the chlorine level is higher than what is recommended for public pool water.

I hope you are not getting chlorine from well water at the tap.

 

[Caryc]

(quoted from post at 15:50:40 11/01/22)

(quoted from post at 17:25:00 11/01/22) I've always been told the chlorine in tapwater will damage a battery. I'm sure some places the chlorine level is pretty low in tapwater but in my area the chlorine level is higher than what is recommended for public pool water.

I hope you are not getting chlorine from well water at the tap.

Are you talking about chlorine in the ground water?

 

[farmersamm]

Without reading all the replies......................... A battery generally doesn't need water unless the regulator overcharges it, and boils the water out. This isn't very common these days.

Any water will do. At the point the battery starts to need water, it's on it's way to the great beyond. Just add water, and put some money back for a new one that's gonna be in your near future.

 

[Stuart]

Since you dont exactly know what is each sample of water from all wells unless you test the water before you add it to the battery, you dont know what exactly what is in the water. ONLY USE DI OR DISTILLED. You just proved my point.
Also, you could call all cars blue if you read the paint formula sheet and see that each color does have blue in it

 

[Caryc]

(quoted from post at 17:39:46 11/02/22) Since you dont exactly know what is each sample of water from all wells unless you test the water before you add it to the battery, you dont know what exactly what is in the water. ONLY USE DI OR DISTILLED. You just proved my point.
Also, you could call all cars blue if you read the paint formula sheet and see that each color does have blue in it

I think we all know the primary colors. I learned it like in the first grade.

 

[Ted in NE-OH]

I use Reverse Osmosis water.

 

[Caryc]

(quoted from post at 18:27:55 11/02/22) I use Reverse Osmosis water.

Hmmm...we don't have any reverse osmosis ponds around here.

 

[PJH]

In the 60's and 70's I had a part-time
job in our small town full service gas
station. New batteries were delivered to
the station dry. When a customer bought a
new battery we would fill the selected
battery with liquid from a bladder box.
We called the liquid ''battry acid''. The
bladder box may have contained a diluted
mixture of acid and water - I don't
remember reading the label. We treated
the liquid with respect, but I gave the
chemical makeup no thought. A short
charge, a short load test and they were
either installed in the customer's
vehicle or carried to their pickup for
them to install at the farm.