# Development of Nickel-Zinc power system for powered wheelchairs

> **NIH VA I21** · VETERANS HEALTH ADMINISTRATION · 2024 · —

## Abstract

The power systems for powered mobility devices (power wheelchairs and scooters) have largely remained
unchanged for decades. They all revolved around Lead-Acid batteries, but some more recently have started to
use Lithium-Ion batteries for their lighter weight and higher energy density. However, there are still limitations
to both of these current battery technologies related to charge rate, range, fire and explosion safety, and
environmental concerns.
Studies have shown that power wheelchair users travel can travel over 10 kms/day and that the distance
travelled is impacted by the accessibility of the environment and the type of activities in which the user is
participating. However, current battery technology largely restricts the power mobility device users to the
distance that the device can travel on a single charge, no matter how accessible the environment is. This is
because the current batteries used require 5-8 hours to recharge. Because of this, most power mobility device
users will charge their device overnight and then use the device the next day on that single charge. While this
appears to be sufficient for most users on most typical days, there are some underlying factors. Firstly, power
mobility device users have become familiar with the range that their device can go and have planned their days
around that range. Secondly, there are many times when power mobility device users may want to go farther
than they do on a typical day, such as vacations and other leisure activities (e.g., sporting events, tours,
concerts, etc.). Powered mobility device users have reported that they need to plan daily activities around the
distance that their chairs can go and at times have had to change plans based on the charge status of their
batteries. Powered mobility device users have also expressed a strong desire for more research on the
development of new and alternative power sources for powered mobility devices. This is primarily due to the
limited range and long charge times.
Nickel-Zinc batteries may provide many advantages over the current Lead-Acid batteries including: higher
energy and power density, higher cycle life, higher charge rate, more recyclable, safer, and less susceptibility to
extreme temperatures. Many of these characteristics are superior to Lithium-Ion batteries as well. The
limitation with the Nickel-Zinc batteries that are most similar to the Lead-Acid and Lithium-Ion batteries is
that they need to be discharged at a rate of more than 40 amps or their life-cycle is significantly reduced. This
makes them not suitable for a direct application in powered mobility devices as typical powered mobility
devices use 0-20 amps during use. Supercapacitors, on the other hand, can be repeatedly charged and
discharged at any rate for millions of cycles, but have low energy density (meaning they can’t hold much energy
in a small package).
The goal of this project is to develop a new power system for powered mobility devices using a combi...

## Key facts

- **NIH application ID:** 10800981
- **Project number:** 1I21RX004626-01A1
- **Recipient organization:** VETERANS HEALTH ADMINISTRATION
- **Principal Investigator:** Jonathan Duvall
- **Activity code:** I21 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2024
- **Award amount:** —
- **Award type:** 1
- **Project period:** 2023-11-01 → 2025-10-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10800981

## Citation

> US National Institutes of Health, RePORTER application 10800981, Development of Nickel-Zinc power system for powered wheelchairs (1I21RX004626-01A1). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10800981. Licensed CC0.

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