I think Mileage will be the issue on cheap models alright for daily commutes but days out may be a issue depending on charging points on the journey plus time to charge if not at the destination.
I have seen a couple of second hand electric cars for £12k ish but they only do just over 100 miles and I guess that was when new mileage figures so may be below that
VW (and others) have City Cars coming that will break the 20k mark.
Just under £22 grand and 200 miles.