Proterra Inc., which makes heavy-duty electric vehicle components like chargers and batteries, filed for bankruptcy on Monday.

The Burlingame, California-based company listed assets and liabilities of at least $500 million each in a Chapter 11 petition in Delaware. The filing gives Proterra protection from creditors while it finds a way to repay them.

Proterra has business units that make EV batteries and chargers for original equipment manufacturers as well as a division that produces entire buses, according to regulatory filings. Through the end of 2022, most of the company’s revenue came from selling electric buses.

The company went public by merging with a blank-check company in June 2021. Since then, its shares have fallen from more than $15 to less than $2.