Powerizer Lead Acid Smart Charger (10 A) for 12V Lead Acid Battery for Worldwide Use

I bought this charger to maintain a 20Ah "gel cell" battery that runs one of the 12Vdc pumps that pressurizes our home well-water system. I was concerned when I ordered it that it would be "stupidly smart" like so many "smart chargers" these days, and refuse to function when faced with the widely varying loads (0 to 10A) as the pump cycles on and off.

But to my pleasant surprise, it "Just Works". When the pump cycles on, the charger's red "charging" LED comes on, and some time after the pump cycles off, the charger cycles back to maintenance mode.

My only quibble is that the cooling fan in the unit never turns off -I would rather that it had a thermostatic fan, so that perhaps the fan wouldn't wear out as soon.

But it has nonetheless run flawlessly for two months now, in 24/7 use.

I am buying another one as part of converting the second pump to have power-outage functionality. Wish I could buy it directly from Amazon, but it is only listed here, not sold here.

-if you have a well system, read on --

The 12Vdc "flojet" style pumps and batteries combined with an unpressurized water storage tank combine to replace the more conventional pressure tank and centrifugal pump, and provide for about 100 gallons of water delivery during power outages.

Instead of storing energy as air pressure, I store it as battery power.

Large pressure tanks are getting harder to buy now that Home Depot has abandoned carrying such items, and even a modest one costs more than my whole battery+charger rig -and the 12Vdc pumps consume much less power per gallon than a centrifugal pump, while delivering a city-water-like 70-80 psi water pressure.

And the water pressure doesn't cycle up and down by 20 PSI, making for much nicer showers!

The resulting system is equivalent to what you find in a $300K class RV, but with two pumps instead of one. It happily handles showers, home laundry, dishwasher, and other normal residential water use. A separate, lower pressure system (off of the same well) does outside water chores.