Over Filled Battery

I think anyone who looks after their batteries has made the same mistake. I have always just left it. Filling it to overflowing would require some sort of a decant though. The levels between the cells would not be exact anyway.

Suck it out with a battery hydrometer,not siphon with a hose and your mouth ha ha,or it will eventually boil out once you start charging it and make a mess.

I wouldn't 'suck out the excess...."

"..When your battery was filled originally it was filled with an acid/water solution. The acid doesn't evaporate, but the water in the acid does evaporate, leaving a somewhat more concentrated acid in the cells. (assuming the battery doesn't burp out acid from the overflow tube)

When you fill the cells, you're just adding water (thus the need for pure water) to the acid to get it back to it's intended dilution.

If you overfill the cells, you're diluting the acid slightly. If you remove some electrolyte from the overfilled cells, you're removing some acid. You can't remove just the water once it's mixed with the acid. Theoretically, you could save the electrolyte and use it to refill the cells at some future date, but that's impractical. You could test the specific gravity of the electrolyte at some future date...."

So based on the above that cell would not have the correct acid/water ratio

I would discuss this more with a professional battery supplier -batteries are expensive and you don't want to get it wrong

Bearing in mind that there is some 'swell' in the electrolyte during charging, and provided that the electrolyte level is not so high as to overflow from the vent, then simply leaving it as is will cause no problem.
The amount of "dilution" would be very small and of no consequence. The excess water will eventually be consumed by electrolysis.

Phil,
just buy one of these and your problem will be solved. I use one all the time for different applications including measuring out chemicals.

Oil syringe

My solution was to take out as much of the fluid as you can and put in largest diameter dish you can find and leave in sun and wind to evaporate. This way you can reduce the water without losing the acid. Just put back in battery when the volume has reduced enough.

I got good at this as it was a common occurrence, at least until I got glasses. Makes one hell of a difference when you can see.


Neil

HI
Never leave a battery overfull .It will spill out of the over flow vent and cause corrosion.Also corrodes terminal . Even a thin film corrodes badly .
Remove with a hydrometer or syringe .
The big question is What were u filling it with ?
U can buy a rubber neck battery filler that fits a coke bottle etc U just stick your thumb over the end to stop flow . The better ones have a breather tube also [provides a constant flow out of the bottle ]

Distilled water off course

swampfox

Of course prior to commencing this apparently complex & involved task be sure to have reviewed the electrolyte SDS, ensure that the vehicle is fundamentally stable, vehicle has been ilsolated and that all required PPE is worn.

If you inadvertently over fill with distilled water (as you did), immediately remove sufficient to regain correct level.
The existing acid solution is of a higher density (SG) so the added water will be initially sitting on top as a strata level.
Of course this will only be until the battery charging is recommenced.
Otherwise I would not be too concerned, modern charging systems closely control against over voltage causing boiling/gassing.
mike