Mike, Im not sure if this is the 2008 eZip now avail from walmart. I did buy the 2007 model and had site-to-store shipping(free shipping). then called Currie directly and bought the 2nd battery. They do slide and lock into the rear carriers as the picture illustrates. I have only performed one test on a kinda windy day..Im guessing about 10 miles and I really did NO pedalling. then I switched to battery 2. Ill be putting a speedo on it for a few more tests, I still say go for it !! The 2008 model at walmart looks good. Side note, My 2007 has road tires w/o the usual mountain bike tread so the bike does roll good. Im liking it !