I get what you are saying about trying some 125Ah batteries, which are much more available and less expensive, but I think I read somewhere that for a 2-wire pump, I should over-estimate a bit on the inverter and batteries for this system. And I could do 4 of these batteries instead of 2 of the larger size, but available space begins to be a consideration. I'd rather not find out the hard way that I undersized the batteries for this project, and if they last me a while will be money well spent. The batteries would be located in a basement where it stays relatively cool. In the end, I look forward to using some of the components down the road for other home loads.