Regenerative Braking

[Barrie1956]

I love the idea that my car recharges the battery, using the braking effect of the motor. I’ve always tended to control my speed, using the gears in every car I have driven. However, is it just me or do you get a very different braking action with the petrol engine versus the electric? I can kind of see why that might be, but it’s messing up my driving style, having these two (apparently different) behaviours.

 

[greendwarf]

Like you I have been driving geared cars for too long to be able to dispense with changing down to slow the car - so I use the joystick to increase the B setting to get the same effect. Of course, you have to be in B0 in the first place. The only exceptions are when under Cruise Control I use B5 and cancel the CC to initially "brake" and on twisting roads where B5 and the foot control avoids all the frequent "up & down the gears" this sort of driving would normally involve.

As high speed in Parallel mode the ICE drives the front wheels directly through a fixed gear, engine speed is related to road speed. So lifting off the gas should have a "braking" effect. However, with the momentum of a 2 tonne car this is limited and "engine braking" in an ICE car is only really effective by changing down the gears. So in the PHEV this can only be mimicked by increasing the B setting, unless already in B5, as described.

 

[Barrie1956]

Quite so, greendwarf, but do you find a difference between behaviour of the petrol engine and the electric?

 

[mellobob]

Pressing the brake pedal doesn't necessarily put on the physical brakes It will engage regen up to a point and then the pads-on-metal. The point is determined by the car's software ... current speed, current battery level and the amount of foot pressure all go into the calculation.

 

[ThudnBlundr]

There is no engine braking. The engine never contributes to retardation as it is only ever connected to the wheels above 40mph and it disconnects when the throttle is released or the brakes are pressed. There is only the electrical regen.

 

[user 5728]

^ This.

My impression too is that the ICE gets untied from wheels immediately when the brakes are hit. Even when just lifting the pedal in B0 allowing the car to sail. Any regen is controlled by the Bs. Speed down, at some point the brakes join in until halt.

 

[jaapv]

There is no engine braking. The engine never contributes to retardation as it is only ever connected to the wheels above 40mph and it disconnects when the throttle is released or the brakes are pressed. There is only the electrical regen.

But tthe paddles simulate engine braking quite well.

 

[littlescrote]

The biggest differences in regen braking levels come from battery charge and temperature.

You cannot put regen energy into an already full battery, if it's more than 80% full you can put some but not much, otherwise it will do a similar level of regen between 0 -- 80% IME unless it's cold in which case it will be lower than when warm. All sensible stuff for the battery.