Daimler’s next iteration of its long-running Citaro city bus will start production in all-electric form by the end of 2018.

Last September Daimler celebrated the 50,000th Citaro to an Austrian capital transport company who ordered 59 city buses, naming it in the process the “most successful city bus of all time.” Americans thus may not have heard of it as it’s mainly in European cities, as well as Singapore, Japan, and Riyadh, Saudi Arabia, but Daimler is enthusiastic that it is now going EV.

To be called the Citaro e-Cell, the electric model will feature a modular lithium-ion battery pack to power hub motors placed at the rear axle, a technology previously shown with the automaker’s G Bluetec Hybrid. Buses will also include thermal management systems that regulate climate control to save power and extend range in an effort to keep battery sizes small.

To recharge the route driver, trolley arms or pantographs mounted on the bus’ roof are expected. According to Daimler, this method of charging would increase weight at the expense of “simplifying architecture, allowing more flexible use of the buses.” This method works similar to Volvo’s 7900e e-Bus, which uses OppCharger and its fleet of overhead charging stations to feed electricity to its mounted connector rails.

No word yet on range, seating capacity, interior features, or when it will hit the streets.

At the moment, prototype testing in two contrasting environments is underway, with several buses running in the Arctic Circle and Spain’s Sierra Nevada. More endurance testing is expected to follow.

“Our city bus produces zero local emissions and is ultra-quiet through town. The engineers are currently undertaking thorough testing of prototypes of the new bus under the toughest of conditions,” said Hartmut Schick, head of Daimler Buses. “As the technical concept, which involves a modular system for the power supply as well as optimised thermal management, makes clear: the Citaro with battery-electric drive will set a new milestone.”

Daimler’s advancement to EV follows a 12-city pledge to run all-electric city bus fleets by 2025. Participating in the agreement, dubbed the “C40 Fossil-Fuel-Free Streets Declaration” are cities such as London, Los Angeles, Barcelona, Mexico City, Cape Town, and Paris, who have jointly launched several initiatives to reduce emissions. Programs have included new London double-decker all-electric buses and Los Angele’s October order for 100 new all-electric Excelsior buses.

Look for the all-electric Citaro to debut at the IAA Commercial Vehicles Show in Hanover, Germany in Sept. 2018.