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Add2 is a leading supplier of real-time testing and simulation solutions. For over 30 years, Add2 Ltd has supplied test systems to automotive manufacturers, universities and aerospace clients worldwide. Please visit Add2’s webpage for further details:


add2 battery graphic Battery storage systems are becoming more and more prevalent as we move towards a distributed energy system, smart homes and electric vehicles. One of the issues facing large battery packs like the ones found in electric cars is that the individual cells within the battery pack become out of balance with each other. This causes problems with charging, discharging, the total capacity or range of the battery pack, plus life expectancy of the battery pack.

The project goal is to explore possible solutions to rebalance battery packs using advanced circuitry and modern materials such as Gallium Nitride power devices. The aim is to provide active cell balancing with high efficiency, small circuit volume and a simple modular approach so the solution can be extended for larger or differently configured battery packs.


Part of the SEND projects involves the large scale rollout of electric vehicles across the Keele University campus. Additionally, vehicle to grid technology will be utilised whereby the plugged in, charging vehicles can be used as mobile batteries for short term grid stabilisation activities. This project can contribute to this by proposing methods to greatly extend the lifespan of EV batteries.

Project progress (June 2019):

  • Literature review completed
  • Test a simple cell equalisation circuit with ideal components.
  • Measure the effects of increasing frequency with performance (equalisation speed) and component size.
  • Currently converting ideal components to accurate models of Si MOSFETS and GaN HEMTs so a direct comparison can be made. 

Business Contact(s): Brett Dowen

Keele Graduate Researcher: Jonathan Carter

Keele Academic(s): Professor Zhong Fan; Dr Jun Cao