I'm just wondering while under regenerative braking, is the car braking with only the front two wheels? And four wheel braking starts when the friction brakes engage? Or does the rear drum brakes always engage even though the front is braking through the electric motor?
regen does not use the brakes. it engages the motor generator to generate electricity. the physical brakes (front and rear) do not engage until you press down hard enough that the motor generator cannot reduce speed quickly enough. because of this, prius brakes tend to last well over 100,000 miles.
sorry, i wasn't clear. the reduction in speed would essentially affect the front wheels, but the braking is done through the motor generator, not the brake pads.
Hmm, I think you're right. It's front wheel drive. Except, maybe the computer applies the rear brakes some too? Our rears wore a bit faster than fronts.
That's a good question, I have not thought about that. I think when slip is detected the friction brakes come on.
Well technically, none of the wheels are braking. However, because the electric motor is connected to the front wheels through the Power Split Device, then yes, the front wheels are driving the electric motor/generator to recharge the battery. See the slight difference? Isn't that the same as a regular car? Why would you want ABS to come on under light braking? It'll come on if detects lock-up (hence the name) so if anything, regenerative braking helps minimise the chance of locking the wheels and sliding on ice since the brake pads are not touching the discs.
The front wheels are braking, ie: slowing the car. Their rotation is being impeded, as usual, in this case by their connection to the electrical motor, as opposed to brake pads, but they're still braking.
Only the front wheels slow the car under regen braking. If a wheel slips on the road surface regen braking is immediately canceled and normal braking takes over along with ABS and VSC. John (Britprius)
