Apr 20

Can Fast-Charging Damage Electric Bus Batteries?

Fast-charging, also called opportunity charging, can be convenient when it comes to charging electric buses. It can lower the charging wait time to 10 minutes, or almost equivalent to the time it takes to refill a fuel bus. Since the battery is one of the biggest investments in an electric bus, it is important to understand how this type of charging can affect battery life and battery degradation over time. 

Fast Charging and Batteries

A new study conducted by engineers from the University of California showed that commercial fast-charging cycles can subject electric vehicle batteries to high temperatures and high resistance causing them to crack, leak and lose their storage capacity.

Commercial fast-charging cycles can subject electric vehicle batteries to high temperatures and high resistance causing them to crack, leak and lose their storage capacity.

The study concluded that “Industrial fast-charging affects the lifespan of lithium-ion batteries adversely because of the increase in the internal resistance of the batteries, which in turn results in heat generation,” according to doctoral student and co-author, Tanner Zerrin. 

Even though this study was conducted at the battery cell level, it is reasonable to assume that fast charging can have an impact on the battery life of bus energy storage systems. Fortunately, there are steps you can take to prevent and monitor any possible damage to your vehicles’ battery packs.

Bus Manufacturers and Fast-Charging

Electric bus OEMs use certain battery types for fast charging cycles, and may even control the charging current and voltage to optimize battery life. So, when choosing your bus, make sure to check with the manufacturer what types and power levels of the charger can be used with your vehicle. Also, read the battery warranty carefully to understand if the OEM specifies any operational limits.

As a general guideline batteries prefer slower current. For example, overnight chargers with 50-70kW, as opposed to opportunity chargers (fast-chargers) that can go up to 350kW are preferable.

💡 If you are curious to learn more about the battery of electric buses such as understanding more about the battery warranty of electric buses or how to prevent battery degradation in electric buses, check out our knowledge center.

How do you ensure your batteries are healthy?


It is important to ensure that your batteries are healthy and that they are maintained over time. Using a platform like the one provided by ViriCiti, allows for real-time fault notifications and historical reports that help you prevent breakdowns and cell degradations. With a fleet monitoring platform, it is also possible to increase your fleet’s uptime, so fast-charging is not as necessary. 

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