Obviously, it's not easy to check for yourself when the brake lights do and do not illuminate under regenerative braking, but whether or not the lights illuminate is a valid safety concern for most owners of plug-in electric vehicles.

To see when the BMW i3 lights illuminate under regenerative braking, BMW i3 owner David Vottero tested it out by strapping 4 GoPros to his i3 and then driving it around town.

The split-screen video is the end result.