Mystery loss of battery fluid

[Rich Stidger]

MS-

Maybe you or someone else can explain why 7 of 12 cells in my US Battery 2200 6V flooded lead acid batteries lost fluid over the winter. Six of the cells lost 1.5 oz and one cell lost 3 oz. These batteries were fully charged, equalized, disconnected, and left on-board this past winter.

All cells measured OC voltage between 6.22 and 6.24 volts this spring. In the fall at the beginning of winter storage these batteries measured 6.48 to 6.50 volts after removing them from charge and disconnecting them.

All of the batteries have water miser type of caps that return water to the cells.

I have seen this type of fluid loss previously, but in this case I cannot find any reason for this to have occurred.

Any ideas?

 

[Benny17441]

Rich, you have three choices, 1) evaporation, 2) electrolysis or 3) leak or spillage. Check the casings.

 

[Chief RA]

With multiple batteries affected it sounds like 3 choices; evaporation, evaporation or, evaporation. Chief

 

[Benny17441]

With multiple batteries affected it sounds like 3 choices; evaporation, evaporation or, evaporation. Chief

That is also my first choice, Rich, check those "water miser caps" to see if they do any good.

 

[Maine Sail]

MS-

Maybe you or someone else can explain why 7 of 12 cells in my US Battery 2200 6V flooded lead acid batteries lost fluid over the winter. Six of the cells lost 1.5 oz and one cell lost 3 oz. These batteries were fully charged, equalized, disconnected, and left on-board this past winter.

All cells measured OC voltage between 6.22 and 6.24 volts this spring. In the fall at the beginning of winter storage these batteries measured 6.48 to 6.50 volts after removing them from charge and disconnecting them.

All of the batteries have water miser type of caps that return water to the cells.

I have seen this type of fluid loss previously, but in this case I cannot find any reason for this to have occurred.

Any ideas?

Rich,

If you checked the electrolyte after charging, and especially after equalizing, the levels will be higher than when the battery is in a rested state. I have seen a number of battery cases leak, usually between the cover and the case, where it is bonded together, but never seen a disconnected battery not being charged lose or use water unless there was a leak..

 

[Bill Roosa]

I'd tend to agree with MS, evaporation in winter.......don't make no sense.
frozen cells cracking cases........
how cold did it get this winter?

 

[Maine Sail]

I'd tend to agree with MS, evaporation in winter.......don't make no sense.
frozen cells cracking cases........
how cold did it get this winter?

Not cold enough to freeze batteries at 12.5V....

 

[Don S/V ILLusion]

Water can and does, albeit slowly, evaporate in cold ambient air. How quickly depends NOT on temp but rather on the amount of moisture in air, i. E., humidity.

Im not imply that is the cause in this case but you cannot exclude evaporation simply because of temperature. In the absence of any other logical cause, it is quite possible.

 

[Rich Stidger]

Thanks for the ideas. Before charging and equalizing in the fall, I made sure that the level was proper in all batteries. As MS stated, the level rises when charged and/or equalized. So perhaps my cells had gassed and lost some water due to the fall charging/equalization. I did not add any more water in the fall after charging because it looked OK and besides that I normally only add water before charging.

So now in the spring I see a low level in some cells- does this indicate that I have some cells that are deficient? I am starting my 5th year on these batteries, and the performance last year seemed up to snuff.