CA 3.2b backpedal regen min speed

[SRB22]

Hello,

I noticed something strange on my bike with a CA, firmware 3.2b: when I brake with ebrake levers + throttle, I can brake to a full stop without using the mechanical brakes (more precisely: I can brake down to 2kph, which is set as the regen brake speed minimum in my baserunner). But if I brake with backpedal regen, it suddenly stops braking around 6kph and I cannot reach a full stop - I have to use ebrakes or good ol' brakes.

I went over all the parameters in the CA setup application (and the phaserunner too, just to be sure), but I didn't see anything that looked like "packpedal regen min speed".

Did I miss something? is it a limitation for some reason? a bug?

 

[E-HP]

Hello,

I noticed something strange on my bike with a CA, firmware 3.2b: when I brake with ebrake levers + throttle, I can brake to a full stop without using the mechanical brakes (more precisely: I can brake down to 2kph, which is set as the regen brake speed minimum in my baserunner). But if I brake with backpedal regen, it suddenly stops braking around 6kph and I cannot reach a full stop - I have to use ebrakes or good ol' brakes.

I went over all the parameters in the CA setup application (and the phaserunner too, just to be sure), but I didn't see anything that looked like "packpedal regen min speed".

Did I miss something? is it a limitation for some reason? a bug?

Is the backpedal regen variable? Maybe backpedal defaults to the Brake Out voltage, rather than variable.

 

[SRB22]

Is the backpedal regen variable? Maybe backpedal defaults to the Brake Out voltage, rather than variable.

Thanks E-HP for your answer.

However, I'm afraid I'm not sure what you mean. PRgen->CntrlMode is "Position", is that what you're asking?

 

[E-HP]

Is the backpedal regen variable? Maybe backpedal defaults to the Brake Out voltage, rather than variable.

Thanks E-HP for your answer.

However, I'm afraid I'm not sure what you mean. PRgen->CntrlMode is "Position", is that what you're asking?

I think I could have been clearer. So for backpedal triggered regen (in throttle mode), it works correctly, but using position mode it doesn't regardless of how far back you pedal?

 

[SRB22]

I think I could have been clearer. So for backpedal triggered regen (in throttle mode), it works correctly, but using position mode it doesn't regardless of how far back you pedal?

For ebrake-triggered regen, it works correctly down to a full stop. For packpedal-triggered-position-mode regen (!) it works correctly on higher speeds, but suddenly stops braking under ~6kph.

I hadn't thought of trying backpedal-throttle mode. I'll try and report back!

 

[SRB22]

After testing: backpedal-throttle mode works like backpedal-position mode: it stops braking at 6kph.

 

[SRB22]

Finally I asked Grin and here is what Justin replied:

This is the intended and programmed behavior. When I had it at a lower cutout speed (like 2 or 3 kph) then if you came to a quick stop and then started to pedal again the regen would still stay active as there is a bit of a latency for the CA speed reading to updpate, and it was found by experimentation that 6 kph was about the sweet spot to still get you almost to a full stop while at the same time always allowing you to pedal and accelerate if you come to a quick stop and then start again right away.

Unfortunately there is no spare eeprom room left to make this be a user programmable setting as I'd otherwise wish. But with some better logic looking at the deceleration value I can have a more effective predictive algorithm to get closer to zero, and I may tweak with it a bit in CA3.2b4 release.

I think this fully answers the inital question!