Above the 9 kWh battery is a 0.1kWh ultracapacitor that can harvest 80 to 90 percent of the braking energy, much more than lithium-ion batteries alone can store. As such, it can go 300 km (186 miles), compared to 180 km (110 miles) for a bike with the same battery pack alone.
Because they’re built of carbon, the ultracapacitors are relatively inexpensive and weigh just 10 kg, yet they boost range by up to 65 percent or so. To get that kind of range with a regular battery, it would drastically increase the weight and cost. The revolutionary system allows NAWA Racer to re-use 80 percent of the energy otherwise lost in braking, it gives a 300km urban range and brings weight savings of 25 percent.
