Viewing a single comment thread. View all comments

ramlak121 t1_ja31yyw wrote

Reply to comment by Only_Outcome4297 in ELI5: How does regenerative braking in hybrid + electric vehicles work? by BackyardShennanigans

How does thsi relate to single pedal driving? Any time a reviewer mentions it they somehow relate it to regenerative braking for some reason

1

Only_Outcome4297 t1_ja32b2y wrote

The idea behind single pedal driving is that the Accel pedal also operates as the brake pedal. So if you put your foot down it accelerates the car, and when you lift it up it slows the car down. In an EV, it uses a combination of regen and normal (foundation) brakes to do it. The system is typically called brake blending or regen blending.

4

ramlak121 t1_ja39u8j wrote

thanks!

1

Only_Outcome4297 t1_ja3bo3r wrote

One additional point with noting is that there is a limit to how much energy you can capture during regen - you fairly quickly reach a point where you're putting too much power back into the battery, which risks overheating the batteries and causing damage. It's no different to having a maximum charge rate when you plug the car into a charger. Heavy regen can also cause stability issues, especially on rear wheel drive vehicles - you can't only brake the rear axle without destabilising the car, so the front also has to be braked using the normal brakes.

On most cars, that limit is in the range of a braking rate of around 0.3G to 0.4G. For that reason, brake blending (using both regen and normal brakes) has to be done. Although 0.4G braking is well within most normal braking events, cars will actually be able to brake at a minimum of 0.9G, and some will be able to go up over 1.2G.

Recent battery technology has improved to the point where it's not so much of a concern. As recently as 5 years ago, the max brake rate you could capture regen from was around 0.2G.

2