Longer ranges and longer service life: these are the advantages of the new NMC4 battery generation in the Mercedes‑Benz eCitaro.

From 2026, the fourth generation of lithium‑nickel‑manganese‑cobalt batteries (NMC4) will be installed in the fully electric eCitaro city bus. With its high energy density, the new NMC4 battery guarantees longer ranges and is characterised by a very long service life. Daimler Buses expects a service life of at least 12 years for new vehicles equipped with the latest battery generation.

The NMC4 battery is tried-and-tested technology made by battery system expert BMZ Poland, a company within BMZ Holding, it has proven its worth in large-scale production for other applications and been further developed for use in buses.

The design of the NMC4 battery packs is identical to the currently used NMC3 battery packs, which is why the new battery generation is compatible with the eCitaro following minor modifications to the vehicle. Depending on the planned duration of use, existing eCitaro vehicles equipped with the NMC1 to NMC3 predecessor battery generations can be retrofitted with the new NMC4 battery and thus benefit from increased capacity and longer ranges.

Compared with NMC3, a different cell chemistry composition in the NMC4 battery leads to an energy density that is almost six percent higher, which thus brings about a higher storage capacity within the same installation space. For example, an NMC4 battery pack boasts 111 kWh of energy instead of 98 kWh in the NMC3 battery. In addition, a higher proportion of the stored energy can actually be used for driving. Consequently, the potential ranges without the need for recharging are also significantly increased.

A further, important benefit for customers is the longer service life of the NMC4 battery and the resulting greater mileage of the Mercedes‑Benz eCitaro. This is paired with a reduced need for battery replacements, which leads to a significant reduction in the total cost of ownership (TCO) and minimises the need for recycling.

Regardless of whether a slow and gentle charging process with a maximum charging capacity of 150 kW is used or regular quick charging processes via pantograph with a charging capacity of up to 300 kW are implemented, this battery can be used for longer. Daimler Buses has taken this opportunity to guarantee an eight‑year service life for NMC4 batteries. Optionally, the individual warranty commitment can be extended to up to 12 years.

The new battery generation also scores high marks in terms of safety. For example, with NMC4 batteries, battery monitoring, i.e. thermal monitoring and alerts in the event of overheating, is not only operational when the operating system is switched on (as was previously the case), but also in standby.

Daimler Buses is pursuing a circular, sustainable approach to battery lifecycle management and offers so-called “repurpose” applications after the first life of the batteries in the vehicle. As part of this, the former drive batteries are used, for example, in energy storage systems to balance load peaks in the power grid or as intermediate storage systems in solar and wind farms. Once a battery has reached the end of its lifecycle after its second life, Daimler Buses offers recycling solutions where the raw materials used are recovered to the greatest extent possible.