So...last year one of my size 29 Deep Cycle Batteries tipped in the battery tray (strap came undone) and it lost solution. I believe much of it cooked off from charging and drawing. My trolling motor ran fine, I never realized the issue for about a month as the battery is hidden under storage. I recently checked the cells and there were all low so I added distilled water to bring the cells up, I added a lot of water (20-30 ounces) and could see the lead plates easily and they appeared clean before adding. I tested the solution with a hydrometer and the specific gravity was consistently low on all 6 cells. My other battery, same age, was in the OK range ~1.25+. Both batteries were 100% charged per my Minnkota 2 bank charger's reading.
I assumed I lost too much acid due to the low hydrometer readings so I drained the dilute solution out of the battery and added sulfuric battery acid to the correct level. I then checked the hydrometer readings after the acid was added and the color is now grey instead of clear? The hydrometer readings are right in the 1.25+ zone for each cell, however the solution is now discolored.
I brought the battery to a garage and it passed various tests (load, cranking and surface) and I was told it was OK - but I may have compromised it and messed up its chemistry.
Does anyone have any ideas here? The battery is a few years old but I don't want to be replacing things for fun. Since we still have ice up here I hadn't had a chance to try it. It seemed reasonable to me that the low hydrometer readings were a result of the solution being too diluted, however this grey color is concerning..........
Curious to see if anyone else has any experience with this? Ideas?