Battery acid

[single]

In the past i have always topped up car/boat batteries with distilled water but someone said you should use electrolyte acid? Are they right?

 

[pvb]

No.

 

[Plevier]

No, absolutely not unless you have lost electrolyte by spillage.
Normal gassing loss is only water.
If you add more acid electrolyte you will be increasing the concentration of it.

 

[Hugh Foulis]

The only time I have ever known a battery be topped up with acid is when a new dry charge battery has the electrolyte added for the first time. Otherwise it has always been de-ionised water. Except I have always used tap water

HF

 

[Plevier]

The only time I have ever known a battery be topped up with acid is when a new dry charge battery has the electrolyte added for the first time. Otherwise it has always been de-ionised water. Except I have always used tap water

HF

At the battery manufacturer I worked for, we often did use tap water in production because it was within spec. for our car batteries (we did monitor it), we didn't use it in long life industrial stuff though, or in AGMs.
That was in the Midlands with lovely water. With hard water like we have here in Sussex for example, not a good thing to do at all.
Use your discretion. Stand it a day or two - or boil - to get rid of chlorine, quite damaging.

 

[billskip]

No, absolutely not unless you have lost electrolyte by spillage.
Normal gassing loss is only water.
If you add more acid electrolyte you will be increasing the concentration of it.

Ok if normal gassing loss is only water when I boil a kettle the only gassing loss(steam) is
only water,But it don't go bang if I put a spark in it

 

[Plevier]

Ok if normal gassing loss is only water when I boil a kettle the only gassing loss(steam) is
only water,But it don't go bang if I put a spark in it

That's because a kettle just produces water vapour.
Gassing from a battery is water electrolysed into separate hydrogen and oxygen, it's not water vapour.
The bang is when it reverts to water vapour, releasing the dissociation energy.
OK my words were not academically accurate - but only water is lost from the battery by gassing, no acid is lost.

 

[TimBennet]

Ok if normal gassing loss is only water when I boil a kettle the only gassing loss(steam) is
only water,But it don't go bang if I put a spark in it

But boiling a kettle doesn't break the water down to hydrogen and oxygen, whereas charging a battery does.

The battery looses its water as the constituent gases, not as the gaseous state of its molecular form.