Do electric buses need more durable components?

Remember the Duracell Bunny? It first appeared in a 1970s advertisement featuring an array of toy rabbits playing the drums, and the one powered by Duracell lasted the longest. Today, battery powered buses promise to outlast their diesel-powered counterparts, but what does that mean for parts manufacturers?

Electric buses appear to be the future of public road transport. According to the European Federation for Transport and Environment, every other new bus in the EU was electric in 2024, with zero-emissions sales expected to reach 100 per cent in Europe by 2027. Around the world, Bloomberg New Energy Finance estimates that e-buses will make up 83 per cent of global sales by 2040.

Battery powered e-buses are expected to last up to twice as long as the typical 10 to 15-year lifespan of a diesel bus. For example, Alexander Dennis claims its Enviro400EV will be able to cover two consecutive seven-year contract terms on typical Transport for London routes without a battery change, or typical provincial routes for up to 20 years with just one mid-life change of batteries.

This is mainly because the lack of an internal combustion engine eliminates a host of associated mechanical components, such as fuel injection systems, exhaust treatment equipment and a multi-geared transmission.

In addition to reducing potential for wear and tear, a simpler powertrain with fewer moving parts, fluids and filters also reduces maintenance requirements, so e-bus fleets will tend to need less downtime during their lifetimes.

The combined longer lifespan and increased uptime puts pressure on the vehicle’s components, which should ideally last at least as long as the lifetime of the vehicle to avoid maintenance bottlenecks. It’s clear that durability is essential, but parts in e-buses might experience wear differently to their diesel-powered counterparts.

For instance, the lack of an engine reduces the vibration experienced by components in e-buses. In addition, both acceleration and deceleration are smoother thanks to the electric motor and regenerative braking. This reduces the strain on running gear like steering linkages and suspension.

On the other hand, the batteries in an electric bus add significant extra weight to the vehicle, so they are much heavier. Consequently, steering components must be capable of withstanding additional loads during manoeuvres and provide the same level of reliable vehicle control without adding too much weight themselves.

In addition, e-buses might have less regular maintenance schedules than ICE-powered predecessors. For instance, with fewer scheduled opportunities for regreasing, parts suppliers may have to develop maintenance-free components, like sealed universal joints or sliding steering shafts, which do not require regular lubrication.

Finally, industry wide changes like electrification encourage closer relationships between OEMs and suppliers. Electric bus designs often involve new prototypes and fast development cycles. OEMs benefit from suppliers who can co-engineer solutions and respond quickly to unexpected wear issues.

In addition, OEMs might find that some suppliers unexpectedly discontinue certain commercial vehicle parts in favour of supplying EVs, so might increasingly turn to suppliers that are flexible enough to provide custom parts tailored to the specific needs of battery powered buses.

Much like the Duracell Bunny, today’s e-buses promise to outlast their ICE predecessors. Like the iconic batteries, no other bus looks like them, no other bus lasts like them, but they’ll need parts that can go the distance, too.