I believe from 2014 on they used the bigger battery. I will say in level mode 1, I get tons of miles even with the smaller battery (10.5 amp hours).
I have been over 40 miles and believe I can get as much as 50 on a single charge. My battery works perfectly but it would be very cool to double my range with a spare.
The not so cool part is it would cost me $900 when all is said and done. If for some reason my battery dies before the warranty is up I will be very excited to get the bigger one.
