Having driven many new electric vehicles (EVs), I’ve often been concerned when using 1-pedal drive mode or utilizing an aggressive form of braking regen in hopes that the brake light comes on during aggressive deceleration. Fresh out of the gate, over 11 years ago, Tesla has this simple and rather important feature covered with multi-stage brake lights that illuminated upon certain levels of braking regen. However, many other manufacturers have somewhat missed the idea of enabling the brake light when using certain regenerative braking levels or 1-pedal driving.
I recently had a new BMW XM, which is a plug-in hybrid vehicle. It has regenerative braking, and the use of the feature at its highest level fails to turn on the brake lights upon letting off the throttle. In many cases, the vehicle behind me was visually irritated that my brake lights didn’t come on upon the vehicle slowing at a reasonable rate until it nearly came to a complete stop. As it turns out, BMW isn’t alone in missing the boat on adding to their vehicle’s software to have the brake lights come on upon a respectable level of deceleration through regenerative braking. Hyundai seems to be one that gets picked on in the video below for lack of such a feature when using the nifty 1-pedal “i-Pedal” feature, which aggressively adds regenerative braking upon letting off the throttle and never turns on the braking light.
The video below from Technology Connections cleverly explains in detail what is happening with some manufacturers in omitting the feature of a new EV turning on its brake lights using regen braking, which is not technically a requirement or law in America. The video primarily covers their Hyundai Ioniq 5, which isn’t alone in its “issue.”