Another topic on B levels and coasting

[anko]

After a discussion on a FB page, I did some experiments to determine:
- Does coasting in B0 consume energy from the battery?
- Does the choice of B level remap the throttle?

I monitored several parameters and recorded my findings:

https://www.youtube.com/watch?v=IQeMVTG77OQ&t=165s

Please read he description on the video for some explanations.

 

[Superflan]

Throttle mapping does depend on B level. I’ll demonstrate more when I’ll get the PHEV back from the dealer that is desperately trying to fix it properly (because yes, I refused to take it back a second time without the proof of a proper fix)

 

[anko]

Throttle mapping does depend on B level. I’ll demonstrate more when I’ll get the PHEV back from the dealer that is desperately trying to fix it properly (because yes, I refused to take it back a second time without the proof of a proper fix)

I look forward to it

 

[jaapv]

Throttle mapping does depend on B level. I’ll demonstrate more when I’ll get the PHEV back from the dealer that is desperately trying to fix it properly (because yes, I refused to take it back a second time without the proof of a proper fix)

I look forward to it

+1

 

[crussellsprout]

Interesting, nice tests! Could you do a similar test of the B modes effect on motor power while going downhill (perhaps with pedal pressed at a lower constant value to avoid going too fast!)?

My theory is that the 'throttle mapping' differences between different B modes is conditional on acceleration and/or velocity feedback for a given pedal position. For example, at a high B level like B5, if the sensed acceleration is higher than a reference value for the current pedal position (eg. which may happen when going downhill), the control system may activate regenerative braking despite the pedal being pressed, in order to better match the reference acceleration value. In the same situation except with a lower B level, the control system may not activate regenerative braking (or it may activate a lesser level of regen braking, or perhaps just dampen the power to the motors), in other words it may tolerate a higher deviation from the reference acceleration value. Anyways this is just my current theory based on my observations, as I encounter a decent sized hill on my commute every day and always notice some regen while having the pedal depressed slightly in B5 mode.

 

[anko]

Interesting, nice tests! Could you do a similar test of the B modes effect on motor power while going downhill (perhaps with pedal pressed at a lower constant value to avoid going too fast!)?

Where I live? Sorry, not really ;-)

My theory is that the 'throttle mapping' differences between different B modes is conditional on acceleration and/or velocity feedback for a given pedal position. For example, at a high B level like B5, if the sensed acceleration is higher than a reference value for the current pedal position (eg. which may happen when going downhill), the control system may activate regenerative braking despite the pedal being pressed, in order to better match the reference acceleration value. In the same situation except with a lower B level, the control system may not activate regenerative braking (or it may activate a lesser level of regen braking, or perhaps just dampen the power to the motors), in other words it may tolerate a higher deviation from the reference acceleration value. Anyways this is just my current theory based on my observations, as I encounter a decent sized hill on my commute every day and always notice some regen while having the pedal depressed slightly in B5 mode.

Kinda what I was thinking: The throttle position determines a specific amount of power or (after factoring in all external parameters) speed. When releasing the throttle a bit, the speed must come down to a new target speed. How fast speed comes down depends on B-settings. IN B0 you will be coasting until you reach the new speed. In B5 you will be braking until you reach the new speed.

 

[anko]

Never mind. After my second test this evening, I stand corrected. At lower speeds, the B levels do remap the throttle.

Screen capture of my test (please ignore the Power Needle Gauge, it is wrong): https://www.youtube.com/watch?v=taeRmLKPsTc

See description with video for where to look.

 

[Superflan]

Yeah this last video represents what I was waiting to illustrate

 

[elm70]

Never mind. After my second test this evening, I stand corrected. At lower speeds, the B levels do remap the throttle.

Screen capture of my test (please ignore the Power Needle Gauge, it is wrong): https://www.youtube.com/watch?v=taeRmLKPsTc

See description with video for where to look.

Did I understand correctly that with low power input on gas pedal, at 50km/h speed .. moving from B0 to B5 ... you notice a surge in power .. and the car accelerate ?

That is strange to me ... I always had the impression that with B5 and low speed, I have to push further on the gas pedal ... but my driving style (at low speed, so in urban environment) as been always to accelerate first and let car roll without gas (I was doing this also with my manual ICE cars before the PHEV (now I have only automatic ICE cars and the PHEV ) ... so for me B0 is a more natural way to drive .. but still my perception was that at low speed with B5 I need to use more push on the accelerator pedal ....

 

[anko]

Did I understand correctly that with low power input on gas pedal, at 50km/h speed .. moving from B0 to B5 ... you notice a surge in power .. and the car accelerate ?

No, it is the other way around. Did I write it up the wrong way?

 

[elm70]

Did I understand correctly that with low power input on gas pedal, at 50km/h speed .. moving from B0 to B5 ... you notice a surge in power .. and the car accelerate ?

No, it is the other way around. Did I write it up the wrong way?

Actually it is not written ... or it is not self evident with my quick check on it

Now looking better

I see on video -14kw with B0
And -9kw in B5

Pedal 13%

But then since speed change all the time I got confused.

I did not notice that in fact car was accelerating all the time.

Anyhow ... so .. this confirm my same driving feeling ... with B5 we have situations which we need to press more on the accelerator compared to B0 ...

 

[anko]

Indeed. At least at lower speeds.