rhagfo wrote:
Well I have seen and used this system and looking at it for Link our two 12 volt batteries. We used on golf carts, and like 30 seconds to fill four 12 cart batteries!
If you have a big bank of batteries, particularly if they are difficult to reach, a watering system is a great idea...if it's hard, there's a good chance you don't do it.
As far as fill levels, I've always hear to the bottom of the tube (but keep the slots clear. I looked up a few links and they all agree with that.
https://www.crownbattery.com/news/watering-your-lead-acid-battery-the-basics
PS: I agree with the others 2+ gallons implies either way low on water or you overfilled.