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View my fuel log 2015 Mirage ES 1.2 manual: 49.6 mpg (US) ... 21.1 km/L ... 4.7 L/100 km ... 59.5 mpg (Imp)
When is it recommended to top off a maintenance-free battery with distilled water? Would it somehow lengthen its life as well?
Also, why is it that some maintenace-free batteries still have 6 of those cell covers? I thought maintenace-free batteries are supposed to be sealed (no covers)?
It's not recommended, but some people try anyway. I was referring to the original Hitachi 55D23L, which is (was?) serviceable, with screw-on caps which allow both topping off each cell with water and checking electrolyte.
I suppose if a maintenance-free battery has lost a significant amount of electrolyte, adding some would help. I haven't come across such a scenario, and trying to add water might damage the battery in the process.
I can't speak for all manufacturers, but it is my understanding that they are vents for the charging process. Aggressive- and over-charging can produce more hydrogen gas than can be otherwise held in by the battery case, and a vent is a Huge safety precaution against bursting batteries.
I hope this helps.
Last edited by Eggman; 05-19-2019 at 05:29 PM.
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View my fuel log 2015 Mirage ES 1.2 manual: 49.6 mpg (US) ... 21.1 km/L ... 4.7 L/100 km ... 59.5 mpg (Imp)