If electric cars are ultimately batteries on wheels, shouldn't you have the option of charging one EV with another? You will with Rivian's truck and SUV. Company chief R.J. Scaringe told The Drive in an interview that "Rivian-to-Rivian" charging will be available. While he didn't elaborate on how it would work, the practicality is clear. Much like some newer phones, a friend with a low battery could grab some electricity in a pinch rather than waiting to plug into a dedicated charger.