I am considering an Ebike but the main concern I have is that, like cordless tools, the batteries seem to be proprietary. There are so many new e bike manufacturers and even some established bike companies that are offering e bikes. The thing I worry about is, what if the bike I choose is discontinued by the manufacturer and I can't get a replacement battery? I'm screwed. Is there any battery standard that the e bike makers use that make the batteries interchangeable?