FreeWire Technologies (FreeWire), a startup that creates portable charging technologies for electric vehicles (EVs) and other devices, has closed a $15 million series A round of funding led by BP Ventures, with participation from Volvo Cars Tech Fund, Stanley Ventures, and other investment funds.

Founded in 2014, San Leandro, California-based FreeWire offers a number of mobile charging products, including a device specifically aimed at charging EVs without relying on traditional infrastructure.

Typical EV charging stations require costly installations, whereas FreeWire’s Mobi Charger L2 portable Level 2 charging station can be charged itself from a normal wall outlet and can then be used to charge up to five vehicles in a day, with 30 miles’ worth of power added in around an hour.