Adding Water To Car Batteries

Lead Acid Batteries used in cars were originally not sealed. During their life gradually water would evaporate from the battery. If left long enough that cell would dry out and hence no longer function. Part of the regular maintenance would be Check the oil levels, Brake fluid and then check the levels of liquid in the battery - usually by unscrewing one or more of the filler caps on the battery. You could also use a Hydrometer to check the “acid” in the battery. If you were conscientious you would use distilled water to top up the level of liquid - tap water was alkaline (Hard water areas) which would lead to a faster breakdown in the life of the battery.

Please note: Not all batteries are sealed. Many batteries still can require topping up with water. Some look sealed but the covers still pry off. I got caught on this and assumed that my battery was sealed. It ran low on water and had to be replaced.