Batteries

The Li-ion battery is the most expensive of all the components of this vehicle. I will describe my experiences in this area in some detail. Use this description as a baseline for battery sizing. 

I used a 48V, 30A, 35 AH (amp-hour), Li-ion "QWW" brand rated for use between 200-3000 watt motor.

Whatever the amperage is (30 in this case), is the main matching specification for the controller. My battery came with a warning:

"This battery has a maximum current of 30 amps, so it can only be used on controllers with a maximum current of 30 amps or less."

This size battery provides about X KM of range on fairly flat pavement with only "start from stop" pedaling.

Adding another battery (in series) to this one will bump your voltage to 96V with amperage (and, therefore AH) remaining the same. Your power will be increased to 96V x 30A = 3000W. Be careful with this configuration when applying throttle as well as isolating the circuit from humans, especially kids. Again, this wiring will NOT increase the AH or range, but will increase power. Is it worth it? As consultants say "it depends". See the questions in the Motor section above. 

My suggestion is to use as minimal a configuration as you can initially and, as the cost of batteries ($/watt and $/AH) inevitably comes down, add as needed. Just plan ahead for extra battery packs. Many packs can be stacked within the cowl using a homemade rack system. See Options section .