High Specific Gravity- how to "fix" it

Re: High Specific Gravity- how to "fix" it

And just to confirm, your hydrometer is clean (no oil on float), accurate (pure water = 1.0), and that there are no gas bubbles on the float (if batteries are freshly charged, the electrolyte may be "hydrogenated" and small gas bubbles collect on the float).

And if you check another battery (car, truck) it gives "reasonable" readings.

-Bill

Re: High Specific Gravity- how to "fix" it

If you want to try and dilute the battery electrolyte to normal specifications--this is some math that should help (as always, check the math yourself--never trust anything you read on the Internet).

Example #1 (assume you dump the entire battery contents of 1.30 electrolyte into a clean plastic or glass container and want to dilute with 1.00 spg distilled water down to 1.275 spg):

Let X=amount of 1.00 water you want to add, and assume 1,000ml / 1.0 Liters is the amount of 1.300 liquid electrolyte per cell; the result will be 1.275 spg electrolyte--ready to pour back in battery:

1000ml*1.30 + X*1.00 = (1000ml+X)*1.275
1300ml + X = 1275ml + 1.275*X
1300ml - 1275ml = 1.275*X - X
25ml = 0.275*X
25ml/0.275 = X = 90.9ml of 1.0 spg distilled water per 1,000ml of 1.30 electrolyte

The other method, assume you know that the battery has a capacity of 1,000ml per cell. The cell/battery is charged, and the spg of the electrolyte is 1.300. And you want to remove Xml of 1.30 electrolyte and add Xml of 1.00 spg distilled water to the cell to get 1.275 spg electrolyte (basically, draw out just enough of the existing electrolyte and then add back 1.00 distilled water):

(1000ml - X)*1.300 + 1.00*X = 1000ml*1.275
1300ml -1.3*X + X = 1275ml
1300ml - 1275ml = 1.3*X - X
25ml = 0.3*X
25ml/0.3 = X = 83.3ml (draw 83.3 ml from charged battery, add 83.3ml of 1.00 distilled water for 1.275 spg)

So, charge the battery, draw 83.3ml per 1,000ml of battery cell capacity, then add back in 83.3ml of 1.0 distilled water. Put battery on equalize (for an hour or two--whatever is the Mfg. recommendation) to generate some hydrogen to "stir/mix" the electrolyte with the distilled water.

The numbers look "sane"--so I think I did everything correctly.

But, again with the warning. I have forgotten most of my 7th grade math--so double check my equations and math to your satisfaction before doing attempting the work.

Also, I used a place holder for battery capacity (1,000 ml / 1.0 Liters)--you will have to either measure the amount of electrolyte you drain, or ask the vendor for the cell fluid capacity.

-Bill