Design and Feasibility of a Nickel–Zinc Battery-to-Supercapacitor Hybrid Power System with Active Voltage-Gap Control for Powered Mobility Devices

Powered mobility devices have used lead–acid batteries for decades with some recent designs using lithium-ion batteries. However, both lead–acid and lithium-ion batteries have concerns related to safety and environmental impact. Additionally, powered mobility device users have expressed a desire for new and alternative power sources. Nickel–zinc batteries can charge much faster and are safer and more environmentally friendly. However, nickel–zinc batteries must be discharged at high rates to prevent degradation of the batteries. This project developed a prototype power system using nickel–zinc batteries and supercapacitors to power a scooter. The design uses the nickel–zinc batteries to periodically and quickly charge the supercapacitors which then provide the power the scooter. Testing confirmed that the power system maintained appropriate voltage and current during use and that the scooter was able to perform with the same range, speed, and power as a current commercially available scooter.