Some electric vehicles do not have the brake lights on when regenerative braking is used. Consumer Newspaper found in a recent test.
Regenerative braking allows the driver to decelerate (and momentarily charge the battery) without using the brake pedal, which could also mean it doesn’t fit the brake light, CR found in a trial of electric vehicles by Genesis, Hyundai, Kia and Mercedes-Benz.
Part of the problem is that when relying on stronger regenerative braking, aka single-pedal driving, drivers often depress the gas pedal lightly to transition between acceleration and deceleration. smoothly, CR noticed. And some trams won’t light up unless the driver takes the accelerator off the accelerator completely.
Kia EV6 2022, red, and 2022 Hyundai Ioniq 5
Federal regulations also do not cover the use of brake lights with regenerative braking. As CR notes, Federal Motor Vehicle Safety Standard (FMVSS) No 108, which includes brake lights, stipulates that they must be activated when the main brake (i.e. friction brake) is applied, but does not require requires that the brake light be activated when the service brake is not in use. It doesn’t prohibit the use of brake lights when another vehicle slows down, but it doesn’t require it either.
CR first noticed the problem in 2014 with a BMW i3 test car, but it resurfaced during testing of more recent EVs. Testers found that a 2022 Hyundai Ioniq 5 can stop “almost completely” without the brake lights on, as long as the driver maintains a slight pressure on the gas pedal.
Testers have seen similar results for electric vehicles from other Hyundai-owned brands, including the electrified Genesis GV60 and GV70 2023, the Kia EV6 2022 and the Kia Niro EV 2023. Both the Ioniq 5 and Kia The EV6 all have similar regenerative braking behavior—although They are styled very differently. The Hyundai Ioniq 6 doesn’t seem to have the same behavior.
2023 Mercedes-Benz EQE 350+
Mercedes-Benz EQ models in Strong Recovery mode (highest regenerative level) exhibit even more bizarre behavior. When the speed dropped to about 5 mph and the deceleration slowed down to a quieter stop, the testers noticed that the brake light went off and came back on after about 15 seconds. A Mercedes spokesman quoted in the CR report said the brake lights in question were in compliance with the regulations, noting that there is no need to turn the lights on when the vehicle is stationary and the brake pedal is not pressed.
Functional regenerative braking was first used in the 1960s in American engine Amitron, but did not gain widespread use until hybrid and electric vehicles became mainstream. Automakers still have different views on regenerative braking, with some opting out of aggressive braking, insisting that it is less efficient than the coast in some situations and invite uneven driving.
Tesla vehicles have never before had powerful regenerative braking and BMW i3 is the first model that Green Car Reports has encountered with very strong regenerative ability, meaning you can drive long distances without touching the brake pedal. That approach probably won’t go away. Automakers have even contemplated a future in which Friction pads can be completely removed.
