Some companies consider disposing of electric vehicle (EV) batteries that degrade over time. But what is going to happen to all of the batteries powering EV buses at the moment?
Zenobe is a supplier and financier of EV charging infrastructure and batteries. It has been refurbishing batteries that have come out of vehicles to create Powerskids, temporary power sources that can provide a charging solution to depots with electric buses that do not require upgrading the grid connection.
Founder director Steven Meersman says these batteries can still have 65-70% of life and can be used in other applications. “It’s all about looking for opportunities to use batteries that have degraded over time in their first life and finding uses for them in a second life.”
He goes on to explain that Zenobe would analyse the life of the battery and assess the relevant application before being incorporated into a second-life battery system with waterproof housing. The finished product is accompanied by inverters, power control systems, energy management systems and software that monitors its performance.
They vary in size from 160kWh to 500kWh units up to a 20-foot container offering 1.5-2MWh of energy storage capacity.
Meersman states that the speed of charging depends on the vehicles and the type of chargers. “In many cases, our small portable batteries can charge a truck in one and half to two hours. For the buses that have bigger batteries, it could take four to six hours, but this depends on how many miles were driven the previous day.”
Under what circumstances should an operator choose a Powerskid over a grid connection? Meersman says operators should usually choose both. For example, smart charging software can maximise the benefit of a new grid connection by carrying out load management.
“However, you can only use the grid connection when the vehicles are there. The battery helps by slurping up energy through a straw during the hours your vehicles are out on the road and then make that available when they are in the depot to be charged.”
Despite the benefits, electric vehicle charging does raise concerns because fires caused by lithium-ion batteries can re-ignite after being extinguished by firefighters. As a safety measure, the batteries come with the same built-in protections as smartphones and laptops, including software that monitors temperature and a fire safety system onboard with an inert gas that can remove the oxygen to prevent fires.
“When we install a battery, we always notify the local fire department of its presence and make sure they are trained in how to respond,” Meersman adds.
Looking ahead, Meersman predicts a rapid deployment of this technology as the financial savings and environmental benefits continue generating interest in the industry. “Electric vehicles were really mass deployed on the European continent in 2016-2017, so there is now an increase in the volume of end-of-first life batteries to be deployed in the second life.”