Do car batteries take water ?

Barr

Probably a silly question but do car batteries need to be topped up or are they sealed.

Berty

No batteries and water don't mix well.

They do take acid though but you cannot top it up.

corktina

nowadays batteries are usually sealed. In the old days when I was alive last century, you had to regulalarly top them up with distilled water.

The Real B-man

You can Top it up only with Dionised Water

muboop1

Barr wrote: »

Probably a silly question but do car batteries need to be topped up or are they sealed.

Really old school batteries used de-ionised water afaik. Today however no.

macroman

Lead-Acid batteries sometimes need to be topped up with distilled water due to the water lost during electrolysis whilst charging. If the level drops too low then it can damage the cells.

Depending on the battery these should around 3 caps on the top which screw off (either with a large flat head screwdriver or some just screw off by hand), where you can see the level and cells clearly. Be careful as sulfuric acid does irritate the skin and can burn through clothes - the amount of jeans I've got which are unwearable due to leaking batteries

Large HGV/LGV batteries often need topping up and charging as they are bridged in 2x12v or 4x6v groups which caused advanced deterioration of the cells.

analfabets

macroman wrote: »

Depending on the battery these should around 3 caps on the top which screw off

Car battery would have 6 caps precisely. 2v each cell. As mentioned before most of the batteries these days are sealed.

rugbyman

if you do find you need a considerable amount of water in your battery ,it can indicate that there is a fault in your alternator,which could be overcharging,
(as said above, last century stuff)
Rugbyman

johndaman66

macroman wrote: »

Lead-Acid batteries sometimes need to be topped up with distilled water

Curiosity killed the cat but what is distilled water? Someone once told me its rain water that has fell directly from the sky and cannot be contaminated by any metal, so hence would need to be collected in a non metal container. Is it this simple?

muboop1

johndaman66 wrote: »

Curiosity killed the cat but what is distilled water? Someone once told me its rain water that has fell directly from the sky and cannot be contaminated by any metal, so hence would need to be collected in a non metal container. Is it this simple?

Water that has pretty much all the impurities removed through distilling it.

Basically extra pure water. Tap water contains trace elements of many different things. The idea is distilled water doesn't. Distiled water in theory will not corrode the batteries parts whilst other elements may contain ions which could do damage...

Feel free to correct me, this is all from memory...

slimjimmc

johndaman66 wrote: »

Curiosity killed the cat but what is distilled water? Someone once told me its rain water that has fell directly from the sky and cannot be contaminated by any metal, so hence would need to be collected in a non metal container. Is it this simple?

Distilled water is water that has been evaporated (often by boiling) and then condensed, which exactly what rain water is. It is very pure as it contains very little salts and solids.
However rain water can be contaminated by pollutants in the atmosphere (e.g acid rain). You're correct about the non-metal container.

Deionised water is also a purifed water which contains very little salts and solids. It's just produced by a different process to distilled water and is cheaper to produce commercially since it doesn't involve boiling/condensing. Both distilled and deionised are pure enough for a battery.

I haven't seen an un-sealed car battery in years, I doubt you can even buy them anymore.

As said above if there are removable caps on the cells you can top up with distilled water Shouldn't need to though to be honest.