Drill a hole above each cell big enough to see its needs and then cover it with a sheet of plastic or small piece of plywood. 13
Unfortunatelly, I have batteries on the shelf too hence I could not drill a hole.
There are a couple of companies that make systems like this, mostly for bass boats that have 3 - 4 batteries stuffed into tight places. There are similar for golf carts.
Very interesting watering systems, indeed. As far as I read, you have to replace the original lids. Does it supposed to have a standard dimension? I have two different battery models and the caps look different, too.
Btw, I was concerning about the maximum electrolyte level as I can't see clearly the top of the battery plates. But I found this image:
So do I have to fill it to the bottom of that vent tube? Because I could see it quite well hence I could easily add water to that level.
Later edit: Now I found this one:
Which one is correct?