Hello,
I have an 8 volt battery in my truck. It has been going strong for over 4 years.
I made a little battery charger for mine, that keeps it trickle charged.
I took a small 1 amp motorcycle battery charger. I cut the positive lead and added 4 diodes in series. I used 6 amp diodes that I got from radioshack.
The anode end (the end with the white line around it) of the diodes go toward the battery. The ground side is left alone.
I soldered the diodes, all the same direction, in the positive lead to the battery and then covered the whole thing with heat shrink to make it tidy.
Now when I charge it, it only charges to 8.95 volts. Just the right amount to keep it fresh.
As far as water, I try to use distilled, it has no minerals which can effect your electrolytic balance.
IF you battery is getting dry too often, maybe you're over charging. Check the charging system on the truck. It shouldn't charge more than 9 volts or so. if so, have your regulator adjusted.
Good luck.
Brian
