I am using six 6s 5ah packs for a total of 10ah 66.6v. My pack is 666wh and yours is 768wh.
4 of my packs are 22 cycles old and I got them in january, so 4 months now. The other two packs are a couple months older and have 5-6 more cycles on them making for around 30 cycles on them.
I figured that I need to ride about 4500 miles on my bike the pay for it's initial cost in gas.
Here's another guy's gas/money log that you might find interesting -
http://spreadsheets.google.com/ccc?k...WN091VHc&hl=en