Great product idea! One possible side market: have you looked at adapting the capacitor+battery combo for electric bicycles? It could be a great application: batteries for energy density, a capacitor as a buffer that can be filled quickly in a pinch (for charging while out and about, or from regenerative braking) and the capacitor could be discharged quickly for high-power acceleration. For short trips the capacitor would bear much of the load, saving battery cycles. The total capacity may need to be somewhat higher than 10Ah, but probably not much higher.
Around the same order of magnitude. Some are less than ten, some are more. It seems like most are aiming for about 10-15Ah these days, at 36V, 48V, or higher. Since capacity translates into range, the greater the better.
