eCitaro to Replace Conventional City Buses

October 1, 2018

Terry Costlow

Based on the proven Citaro platform but incorporating design elements from the Mercedes-Benz Future Bus concept, the new eCitaro is poised to almost completely replace city buses powered by a combustion engine in just a few years, the company claims.

The all-electric bus, which made its debut at the IAA Commercial Vehicles trade show in September, reportedly covers about 30 percent of all requirements of transport operators already, solely with charging at the depot. Mercedes engineers believe that figure will jump to 50 percent in two years, when the next generation of lithium nickel manganese cobalt oxide cell (NMC) batteries are expected to become available — with 33 kWh per battery module and a total capacity of up to 330 kWh.

Beyond that, lithium-polymer solid-state batteries, which have high energy density but are not suitable for quick-charging, and fuel-cell range extenders hold potential to allow the eCitaro to fulfill nearly 100 percent of all city-bus requirements.

The current eCitaro revealed in Hannover, Germany, is based on an optimized AVE 130 electric portal axle from ZF with electric motors at the wheel hubs. Peak output of the motors is 2 x 125 kW; torque is 2 x 485 N·m (358 lb·ft). Li-ion batteries, with a total capacity of 243 kWh, are split between up to 10 modules, each supplying nearly 25 kWh. Two battery modules are located on the roof, and four modules at the rear of the bus; another two or four battery modules can be mounted on the roof, if requested.

The design of the roof, with integrated heavy-duty rails for the batteries, is derived from the system used for the gas tanks of the Citaro NGT.