I have been thinking about doing them in parallel. I must admit, before I got it I thought both WOULD be parallel.
My plan was this:
Go to work on one battery, charge 9 hours while I work. Switch to other battery and ride home, charge overnight. I will always have a fresh battery, and it will only be "standby, but full" for about 12 hours or less.
Parallel sounds good as long as I can get them both full in 9 hours with the charger that Currie supplied with the bike. I also wouldn’t mind doing 36V either.
Oh, and a front derailleur!! (here we go, this hobby is gonna get expensive!)