Freeport,
I have the system, have had it in place for 12 years, and am on my 3rd battery, so they do last about 5 years. Maintenance is simple; add distilled water to the batt when the electronic indicator beeps and flashes that it is low.
Yes, water powered would be a better bet if on municipal, but I thought your place was rural, freeport and if so then if you lose electric, you lose your water pump.
I bought my system at Home Depot.