Proper Procedure for Checking Specific Gravity |
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I thought I had been instructed to check specific gravity in flooded cells after equalization but prior to rewatering. The problem is that prior to re-watering the electrolyte level in the cells can vary quite a bit. I created a theory that if the electrolyte level in a cell was low the SG would test inaccurately as artificial high. This theory is based on the assumption that the sulfuric acid volume does not change but the water volume does. If the water volume is reduced, the ratio of sulfuric acid to water (and the Specific Gravity) would increase. |
I did a test on some batteries being maintained. I tested SG before and after rewatering. I found that cells with low electrolyte level tested generally with higher than expected SG and those SG readings decreased after water was added to bring electrolyte levels up to a uniform level. The more water that was added, the greater the decrease in after watering SG readings. |
Here is a link to the spreadsheet in which I recorded my results. |
Tools used: |
Conclusion: Here is the proper order of steps to check Specific Gravity: |