The Information reported on Friday that Rivian Automotive Inc’s (RIVN.O) electric vans for e-commerce retailer Amazon.com Inc (AMZN.O) may have a shorter range than originally announced, citing a driver testing the vehicle.

When the van’s heating or cooling was turned on, the battery drained 40 percent faster than usual, according to the driver.

Amazon, which announced a 20% stake in Rivian at the end of October, bought 100,000 of the company’s electric delivery vehicles in 2019 as part of its aim to reduce its carbon footprint.

The vans’ range would run between 120 and 150 miles, depending on their size, according to Rivian. However, depending on the weather, that range is significantly lower, according to the report.

The prototype van used had as many as 12 cameras inside and outside the van, but Amazon plans to add another four once the vehicles hit the road, the report said, citing Rachel.

Amazon and Rivian did not immediately respond to Reuters’ requests for comment.

Since it went public earlier this month, Rivian has grown to become one of the most valuable automakers, even though it has just started production and delivery of its electric vehicles.

Its shares pared gains following the news and were last up about 4%.