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Old 06-12-2017, 12:15 AM   #26
humfrz
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Quote:
Originally Posted by Gforce View Post
Except for the time issue. Just as you can add water to cooling systems you can add water to batteries. However, to gain freeze protection the water must have a chance to mix with the "antifreeze". In the case of coolant the water needs to mix with the existing glycol mixture. This happens rapidly. With batteries it needs to mix with the sulfuric acid mixture. That takes quite awhile. Do not top up your battery in freezing weather, it can bust the case.

In reality, low maintenance batteries are worn out by the time they need water. Just replace it.
Well, now, @Gforce ...... I think you are splitting molecules here. Yes, the specific gravity of sulfuric acid is higher that that of water and in a weakly charged battery, acid stratification can take place.

However, in a healthy battery (fully charged), since the added water is soluble in the existing acid/water electrolyte solution, and the amount of water added is usually relatively small, and a battery in a car usually gets jostled around, thus mixing the added water to the electrolyte ..... the chances of the added water freezing and busting open the case are very small.

Besides, I've been adding water to batteries in the wintertime (living in OH, MO, CT and Europe) for the past 65 years and never have had a battery freeze and bust open.




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