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[trikester]

I posted this on my e-trike thread but those who aren't interested in that subject will have missed it. I had Harlan re-program my 2013 SPORT mode system to 0% regen with no brake light and 15% with light. Then I iPod programmed the ECO for 0% with no light and 25% with light. This gives me coasting almost as good as a bicycle and then two levels of regen when I put on the brake light (but not the brake itself unless extra stopping force is needed).

The question I had to answer by trying was: When the SPORT regen is set to 0% does the ECO regen drop to that same level when it is programmed for 0%. The answer: Yes.

As I have stated before: When slowing is not needed, the most efficient way to go down a slope is free coasting with no regen. When slowing is needed then use regen for that.

Now the bad news: The 2012 systems cannot be set to 0% regen because by default it goes back to the factory 7% the next time the key is turned on. If the Doc, or someone else, can figure out how to defeat that setting then 2012 riders could benefit from this ability to get good coasting also. It is very nice to roll down a gentle slope without using any throttle.

I'll copy this reply to 2013 also under "regen settings".

Trikester

[Doctorbass]

That is excellent info, Thanks Trikester.

Well i think it would be nearly impossible to acheive that on the 2012 because i think  the MBB reprogram the sevcon  to set the baseline program parameters every time it is switched ON.

That would require to play with the MBB firmware rater than the sevcon i guess...

Doc

[Le Z Turbo]

Thanks for this info to program my DS Eco mod !
Laurent

[NoiseBoy]

I coast all the time. Just open the throttle a touch. I never really saw it as a problem.

[dkw12002]

I like just the opposite...max regen with the brake and with no throttle. Otherwise I find myself coming up too fast behind parked cars and into corners. I suppose I could get used to coasting if I had too, but my other motorcycles engine brake and I'm used to that. Off road I might feel different about it too.

[emotofreak]

As I have stated before: When slowing is not needed, the most efficient way to go down a slope is free coasting with no regen. When slowing is needed then use regen for that.

Trikester

In theory I agree with this statement. However, a recent empirical test generated an interesting data point. My buddy and I were both on '13 Zero S's, we both started at the top of a long (~3miles), fairly steep hill, that had a 1/2 dozen or so corners that required minimal braking. He turned his bike off and coasted the entire distance, using the brakes when necessary but otherwise staying at or above the speed limit the whole way. I paced him, using as little throttle as I could, as little brake as I could, and allowing the bike to regen as much as possible.

The end result? I gained 1% SOC. He obviously ended the same as he started. The moral to the story? It is at least sometimes better to regen than purely freewheel.

I just love watching the SOC go "UP" while riding. That will never get old...

[Biff]

As I have stated before: When slowing is not needed, the most efficient way to go down a slope is free coasting with no regen. When slowing is needed then use regen for that.

Trikester

In theory I agree with this statement. However, a recent empirical test generated an interesting data point. My buddy and I were both on '13 Zero S's, we both started at the top of a long (~3miles), fairly steep hill, that had a 1/2 dozen or so corners that required minimal braking. He turned his bike off and coasted the entire distance, using the brakes when necessary but otherwise staying at or above the speed limit the whole way. I paced him, using as little throttle as I could, as little brake as I could, and allowing the bike to regen as much as possible.

The end result? I gained 1% SOC. He obviously ended the same as he started. The moral to the story? It is at least sometimes better to regen than purely freewheel.

I just love watching the SOC go "UP" while riding. That will never get old...

The statement previously made is still correct.  He stated that if you don't need to slow down, coast, but when you need to slow down, use {only} regen if possible. If the rider with their bike off didn't use their brakes at all, I would be surprised at the result of your test.

-ryan

[Doctorbass]

Hey Biff, Great to hear from you again!

I would love to know if there is any kind of 75-9 motor version on the 2014 but i know all people from Zero have to shut their mought until next 5 nov 

That 75-7 motor is really a tempting mod to do on my S 2012 if combiend with a size 6 but without any voltage increase i doubt that the 75-X motor could improove anything...

Ok ok now back to the original thread! 

[Le Z Turbo]

Interesting thread... So I changed my ECO settings to 0% regen coast and 100% regen brake.
I must say it's a all new way of driving, trying to be as gentle as possible on the front brake switch when you want regen and feeling the "freewheeling" when releasing it. Really different than an ICE bike but surely effective for range improvement.
I'm gonna try to get used to it next few weeks of riding.
Laurent

[Justin Andrews]

  i doubt that the 75-X motor could improove anything

Aside from the 75-X's motors possibly having a more robust sin/cos encoder...

[trikester]

emotofreak didn't read my statement carefully. The reason he came out better is because the other guy used his mechanical brakes. I repeat: if slowing is not needed - free coast. If slowing is needed use regen.

I have my ECO mode set for 0% regen without brake light and 100% regen with brake light (which comes on before any mechanical braking).

I said all of this in my original statement.

BTW - Even slight throttle needed in order to go downhill is using energy. I'd rather coast!

Trikester

ALSO: Biff has told me that the firmware upgrades to the 2012's MBB and Sevcon removes the auto reset to the SPORT default regen and also removes the limitation on how many times you can switch to ECO and back to SPORT. That is definitely an upgrade worth getting. The 2012's then become like the 2013's in that regard.

[Doctorbass]

ALSO: Biff has told me that the firmware upgrades to the 2012's MBB and Sevcon removes the auto reset to the SPORT default regen and also removes the limitation on how many times you can switch to ECO and back to SPORT. That is definitely an upgrade worth getting. The 2012's then become like the 2013's in that regard.

That is very good new!!

On my side i was only able to make the sevcon upgrade but not the mbb since no dealer in Quebec province have the up to date MBB programmer!
Doc

[emotofreak]

I was only adding the data point, that even with just minimal braking required, the regen proved itself superior to freewheeling with empirical data. I was not arguing the original statement, in fact, I explicitly agreed "in theory". I guess what I'm getting at is, is there a scenario, that can be performed in the real-world, in realistic conditions, where turning off the bike and freewheeling would actually give you better range? You would have to know, ahead of time, that you will not need the brakes or throttle. It seems that is a small corner case, and one for which I have not seen empirical evidence to support. Again, I agree "in theory" a freewheeling bike should use less energy in a very narrow set of circumstances. I'm just not sure all those criteria will ever be met in the "real world". Basically if we go for a ride, and you turn your regen on/off all you want, and if I am just pacing you in eco mode, I will still probably go further.

Ultimately, I know we are all interested in getting the most efficiency out of our vehicles, and I am just as curious as the rest of you as to what the best possible drive profile and strategy is. My best guess at this point, as supported by all the data I have access to, is no-regen-freewheeling will provide little, if any, perceptible increase in range in any realistic scenario. While effective management of regen can provide up to 6-8% increase in range in an optimum duty cycle. Possibly clutching the motor/drivetrain out of the loop entirely would make such a strategy more effective, but I think we are reaching the point of diminishing returns here.

Just thinking out loud.

[trikester]

I am experiencing pretty good coasting now that I have the "no brake light" regen at 0%. Because I don't have to turn the bike off to get this I can instantly get max regen, when I need to burn off speed, by lighting the brake light.

If no braking is needed then coasting is always going to be more efficient than any amount of regen because with any amount of current flow there will always be IR losses. Same with a small amount of throttle. The differences would be small but I would expect it to be measurable. In the case of your friend he was using brakes, which of course don't return anything to the battery, so you definitely would go farther in that test. Also in any test there are differences in bikes that have to be evened out. My first Zero had a construction fault in the rear hub that added a lot of drag. Zero eventually replaced it.

The best way to run the test would be to swap bikes with one set up with 0% no light and 100% with brake light regen and one with 7% (the factory default) and 100% (with light) then swap the settings and run again.

Trikester

[BSDThw]

I don't know the 2013 so good but I think it is the same. If you have the bike ON and push it you will feel and hear that the motor gets some regulation and the bike has a higher rolling resistant. Therefore the coasting is not really "free".

Last year I did a lot of testing different parameter in the Sevcon. There is one special Register that switch off the H-Bridge if no torque is required.

4650h                   

Miscellaneous DSP configuration           

Used to disable/enable various features on the DSP
Bit 0: Disable encoder wire-off detection
Bit 1 : Disable software over current
Bit 2 : Use low speed gains
Bit 3 : Enable closed loop slip compensation
Bit 4 : Scale max torque by power limit
Bit 5 : Used fanned I2t cutback profile
Bit 6 : Allow drv/brk trq inhibit to 0 RPM
Bit 7 : Enable motor open circuit detection(Nano only)
Bit 8: Enable speed dependent field weakening
Bit 9: Short/Open circuit motor during severe fault
Bit 12: Disable bridge if motor spinning and demand = 0 (PMAC only)
Bit 13: Make fwd+rev speed limits equal and opposite
Bit 15: Enable PI based Iqmax limit (PMAC only)

Be careful when changing you should not change things you don't know what it will do! You can easily hurt/kill yourself!

I had this setting for a while and it was coasting really "free". I will test it again because with my step less regn brake it will be interesting how it works. (the brake is like the throttle and will  demand torque => costing than braking will show how this react )

What I can remember I had sometimes a delay (dead-time) when coasting to acceleration (~ 1second).

So I will test it again!