Electric bus manufacturer Proterra Inc. set a range record for heavy-duty electric vehicles, running 1,101.2 miles on a single charge using a 660-kilowatt-hour battery.

The record-setting ride took place at the Navistar Proving Grounds in Indiana on a test track using an empty bus, with the experiment designed to alleviate concerns by electric vehicle drivers over driving range.

In addition to the 1,101.2 mile ride, the bus’ E2 battery pack set an energy record with 160 watt-hours per kilogram, which bests the previously cited high density of 140 watt-hours by California Air Resources Board in its 2016 bus battery report.

For the long-term, Proterra has also announced ambitious plans to produce 500,000 kWh of E2 battery packs every year at its new manufacturing plant in Burlingame, Calif., in collaboration with LG Chem, a South Korean battery manufacturer. These battery packs would be exclusive to large transport vehicles such as trucks and buses.

A lot of obstacles still remain however before Proterra affects public transit for good. Increasing competition from electric bus and truck manufacturers such as BUD Motors has encouraged the company to diversify toward commercial trucking. Also, pressures to reduce emissions while keeping fuel and maintenance costs low is a primary focus of bus fleets, given its electric vehicles’ high initial cost.

According to Foothill Transit, a Proterra client, a Proterra electric bus costs $689,000 after incentives, compared to natural gas buses costing $550,000, figures cited by the American Public Transportation Association.