I thought I'd introduce my D8 build. My main objectives with this were:
- Get run times of >20 minutes on one battery.
- Have a safe handling car
- Have good weight distribution
So, considering with my last car, I got 11-12 minutes (say 11.5) out of a 4350mAh 14.8V pack (64.38Wh), I needed a battery change to finish a 20 minute final. So, in total, for 23 minutes, that's 128.76Wh needed.
I decided to use two 18.5V packs in parallel (at 61.05Wh each) for a total of 122.1Wh. Theoretically, at least, I should be good for 21.8 minutes run time. (122.1/128.76 = 0.94827, 0.94827 * 23 = 21.8 minutes).