Bought 2 640ah and used them over the summer charged them with 1350 watts solar and never had a shortage of power, coffee maker, toaster, microwave, 2 12v fridges 4 cu ft and 10 cu ft constant television, and of course lighting. In Alberta we don't always have sunshine like they say, this year it rained everyday in May and June sometimes morning sometimes afternoons so solar was not always abundant, but we never had a shortage. I have been in contact with support over some questions I had, and Alice is my rep she is 100% always prompt always has the answers, give that lady a raise. Thanks Alice Thanks Humsienk.