A neighbor bought one at Lowes and I noticed it takes him 2 days to mow.
I had the electric weed eater and couldn't get done on one change. And after winter the batteries wouldn't work. Personally, I'm sticking with gas.
I've got a battery weedeater and its batteries match my drill. I have a large yard at the new house (had even more to trim in fenceline and used it for edging on the old house corner lot, etc) with no issues, but then I have more than one battery. Lithium Ion batteries are better than the old Nicad and as far as winter, I bring the batteries in and keep them in the basement over the winter and have been going strong on these for several years now.
Lawn mower would be a no go as I have about .6 of an acre here and it would not handle that, I'm sure.