I've got a customer wants a price for installing a generator back up for their water pump, this gives them water pressure within the house, (when the power goes off, so does the water), has anyone done this using deep cycle batteries, an inverter and a trickle charger?, either on a change over switch, or even set up to run permanently this way? just thinking that if this is the only thing they want the generator to run, the cost of the generator etc and the fact that someone has to go out and start it could make alternatives worth looking at??