Good find, Bob! I was given 12 about a year ago, by a guy here in Ballarat, Vic. who had them in his electric car. I think officially theyr'e known as golf cart batteries, and the 105 is measured at the C10 or 5 rating. At C100 they are probably around 140 AH. When they couldn't take the constant 3-400 amp drain any more, he bought newies and I saved him a trip to the scrap metal. He said I should watch a couple in particular, but they got mixed up and anyway, they've all been terrific. In our 24v solar setup we generally dont pull out more than 20 amps on (sort of) average, so I expect a couple more years out of them yet. You should equalize them very regularly, though.