Public transport is electrified worldwide. The UK is expected to have the largest fleet of e-buses in Europe until 2024while London plans to fully electrify its bus fleet by 2034. Today, one-third of Belfast’s Translink fleet is zero-emission, and full decarbonisation is planned by 2030.
Although the total cost of operation (TCO) of the eBus is less expensive than diesel in the long run, initial investment in environmentally friendly vehicles can be high. Intelligent fleet monitoring and charging process management tools can further reduce eBus property freedom. For example, driving style monitoring tools can help operators identify and reduce idle where possible by training drivers based on specific action points.
The battery alone is almost 50% of the total cost of the eBus. Since in the world of EV it is customary to no longer use a battery when it reaches 80% of its original capacity, it is even more important to look at the health of the battery. All batteries inevitably degrade with use, usually due to four main factors: temperature, high power, depth of discharge and average state of charge.
As with humans, batteries work best at 15 to 30 degrees Celsius. High temperatures tend to increase the rate of ions in the battery, leading to chemical reactions that prevent ions from doing their job of transporting energy. Extremely low temperatures also reduce their ability to store energy. Therefore, on hot days it is recommended to stand buses in the shade or under a canopy. On very cold days, parking in a garage can help minimize battery degradation.
Second, if batteries are not optimized for fast charging, it is usually best to avoid high power / current when charging or discharging them. High power causes batteries to wear out faster and shortens overall life. Therefore, lower current and power requests are generally considered best for batteries.
The battery alone is almost 50% of the total cost of the eBus
The third aspect to consider is the depth of discharge (DoD). We can say that the transition from 0% to 50% to 0% is half the full cycle at 50% DoD. Charging cycles directly affect the aging of the battery. The lower the height of the cycle, the better. In other words, it is better to get 1000 charging cycles by charging the battery 2000 times from 50% to 100% to 50% than to charge 1000 times from full to full.
The average state of charge (SoC) also affects the state of the battery. In general, if your batteries are deaf or running close to 100% or 0% SoC, it is detrimental to the health of the battery. Best practice is to use SoC batteries on average 50%.
If batteries inevitably become unfit for public transport, they can be resold to third parties, such as recyclers, to a secondary market or back to the manufacturer. There are also several indoor uses, for example, for tram and railway substations or in combination with bus charging stations.
The views expressed herein are those of the author and do not necessarily reflect the views of Automotive World Ltd.
Alexander Shabert is Senior Director of Global Bus ChargePoint, an electric vehicle charging network operating in North America and Europe
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