Car batteries and the water level.?

Question

Does the water level increase or decrease as the battery is charged?

Its actually a motorcycle battery, and not ALL batteries are sealed. I remember that the electrolyte in the battery will be absorbed in the cell plates but dont remember if its when charging or discharging.

Answer 1

Water level changes with temperature and charge. Sealed batteries are only sealed in that they have the caps put on in such a way that they don't evaporate much water over their life and usually don't need any added. Should you have a problem with the battery you can normally remove the panel covering some of the caps with a screwdriver and check the water. Can also test the specific gravity of it then with a battery tester as well so you can tell if the cells are all good and how the battery is. Only batteries that this is not true for are the "gel" type such as the Optima batteries that have the acid sealed in a gel form and doesn't move or change noticeably over the life of the battery. Can't do a thing with them that I know of except replace if fail to hold a charge. Water expands when warm and contracts when cool so level does change. That is also why when charging a heavily discharged battery they recommend that you remove the caps so that the water and acid won't boil out when it rises up from the heat of charging.

Answer 2

I don't think you need the formula, and I do know that lots of motorcycle batteries, and many others are still having removeable caps! This is because they are strored "dry" the acid is not put in till the battery is sold! This keeps them from deteriorating while sitting "on the shelf"!

Now, the water will go down, as the battery is charged (to some extent), as a little is lost as the hydrogen escapes from the acid!

So it is best to see that the battery is full to the "line" when a dead batery is put on to charge, - (this is to make sure the plates don't become dry from lack of "water")-- dry plates warp and short out! You can"top out" the battery once more , - then it should hold it's level for quite a while!!

Note: that you use distilled water, - not tap water...... tap water has too many impuities in it, and the stuff will settle and short the plates out!

Answer 3

As a battery is charged, hydrogen and oxygen gas is released. However, with the newer car battery designs the oxygen and hydrogetn recombine forming water then it goes back into the plate area.

However, on industrial batterys such as battery powered fork lifts and submarines, the electrolite is checked a minimum of once every 24 hours. Since those batterys are very expensive costing tens of thousands of dollars in some cases, they do check them manually.

when adding water to these kinds of batterys, use only distilled water- the minerals in the water build up on the bottom of the plates, shorting out the battery and destroying them

Answer 4

most car batteries are sealed and you cant even check to see the water level but if the caps are removable then when you charge a battery the water level will go down. it takes many times before you will notice it though. if the water level gets below the plates, then fill it with distilled water. if you don't fill the battery then you will eventually kill it!!!

Answer 5

all batteries now are sealed and the water level stays the same