In this video the fellow adds water to his AGM battery. I never thought about that much but duh, it is done by weight on an AGM, since one cannot just add water and look at the surface level. That is, if the "new" weight is known one can weigh the older battery (after cleaning all the dirt off of it) and just add the appropriate amount of distilled water to make up the difference. (How much to each cell? Well, no level to look at, so probably same amount to each unless there is some other indication that one has less water than another.) Unfortunately the OEM battery True Start S46B24R battery (0054421171325) doesn't have a spec sheet, at least not on the web parts site at the dealers. The Yuasa one does though: https://www.yuasabatteries.com/battery/s46b24r/ which shows the weight as 29.76 pounds. Does the True Start differ from the Yuasa in anything other than the label? Labels don't weight much usually. That the battery could be serviced this way assumes that once the label is cut off there are removable caps underneath to access the cells. That might not be true on this battery. The factory assembled batteries might have the whole top glued on over the cells, or the caps glued to the top. That would make them "Maintenance free" in the "Maintenance nearly impossible" sense.
Speaking for the Yuasa battery; electrolyte must cover the plates. An equal amount above the plates in the 6? cells. The end cells usually requires more distilled water than the ones in the middle. Hope this helps.....
Interesting that the fluid is over the top of the plates. I do recall a video where somebody tilted an AGM battery and the electrolyte could be seen (barely, through the translucent case) sloshing up the side. What are the cell caps like on that battery? Do they screw on one at a time like in that video or are they just "push in snugly as a group of three" like most flooded batteries?
