Variable Regeneration Voltage Questions.

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Jan 31, 2008
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Rhone-Alpes
I am finding regeneration awesome using a Grinfineon 2017 sinewave controller. I'm confused about the technical fine tuning.

When I twist the throttle, the regeneration is not variable relative to the throttle position, the dampening force stays the same.

I have CA23. CA3 is necessary to configure a base ebrake resistance setting. Do I need CA3 for variable regen?

Can I arrange variable regen using CA23, throttle and Grinfineon 2018 48v 40A controller? How do I do it?

When I engage the ebrake, does it switch the throttle line to 0.0V? Does it stay at 0.8V? the ebrake is not a simple switch?

I don't know if the base regen is at low/medium/high strength at the moment. For driveability, it would be cool to have more and less regeneration at will, there are 15% hills everywhere here. If I use regeneration to go down a hill, it will give the same energy if I go slow or fast, so long as I don't get to the T junction too fast and have to switch to rubber brakes?
 
I don't know about your specific controller, but the one I'm using has onboard variable regen which requires a 0-5v brake lever (or potentiometer). The harder you press the brakes, the more regen you get.
 
Your controller is what determines if you get variable (proportional) regen, and how it works.

So you have to look at the manual (if any) for your specific controller (probably available on the Grin site) to see:

--if it has proportional regen

--how it's controlled.

Most of the ones I've seen use the throttle itself to control how mcuh regen, *after* you engage the ebrake lever.

The controler itself has to be programmed for different regen operation, if it has the ability to be programmed, and if there are different ways regen can work on that controller, or different settings available for it.


There may now be versions of the CAv3.1x firmware (check with Grin and/or the CA v3 beta thread) that allow you to modify what it sends via the throttle when the ebrake lever is engaged, but your controller has to know what to do with that for it to do anything. Just having a CAv3 doesn't add proportional regen to a controller that doesnt have it.

The typical controller does not have this function (my 5-year-old Grinfineon does not).
 
amberwolf said it well and concisely...

I am going to add, that although tangentially related, information that might be important to others that might see this thread.
The kelly KEB series of controllers allow for variable regen via a different sensor, BUT the sensor used must be of same kind as the throttle. ie:

if the throttle is a pot(0-5v), the brake must also be a pot(0-5v)
if the throttle is a hall effect sensor (1-4v) the brake must also be a hall effect sensor (1-4v)
they cannot be different, or the controller will not fully turn on, and likely throw a error which is not related to the real problem(sigh)

If you really want to combine say a potentiometer based throttle with a hall effect sensor brake, you need to use a microcontroller (or god forbid some analog solution) to map say a 0-5v signal onto a 1-4v range, which is simple as a ADC --> microcontroller --> DAC.

AFAIK All controllers capable driving a brushless motor should in technicality also be able to provide variable regen, and it is purely a software/firmware/input limitation.

all this is just information I would have liked to see when I was doing research to build my bike.
 
I have proportional regen on the Grinfineon http://www.ebikes.ca/shop/electric-bicycle-parts/controllers/c7240-gr.html#, So i fixed an ebrake on there and using a hall effect twist throttle, and the regen currently isn't a variable regen.

I thought that It would give me variable regen right out of the box, perhaps I have to program the controller differently? It's not switched on to variable mode?
 
http://www.ebikes.ca/product-info/grinfineon.html
Proportional Regenerative Braking: Regenerative braking is easily enabled via a brake cut-off or push button, but now can also be enabled through a Cycle Analyst V3 directly. The regenerative braking torque can be varied by the user two ways. Using the brake cut-off on the controller will apply a baseline 20% regen torque which can be increased by varying the throttle between 1.0V-3.5V while braking. If using a Cycle Analyst V3 with the ebrake cut-off going through the CA3 the braking force can be dialed in by setting the "Brake Out Voltage" between 0.0V to 0.8V, where 0.0V is 100% regen and 0.8V is 0% (motor cutoff). Using the CA3 allows for maximum compatibility with your battery and setup to ensure the regen is dialed in where you want it.
 
Hey, I was a bit confused by that paragraph, I did read it and I thought my hall was 0 to 0.8.
I asked Justin who said:

You will require either a throttle that is bidirectional and has a 0.8-0.0V region for regen control, or the use of a CA3 device which will be able to output such a throttle voltage based on a normal ebrake lever and the regular forwards throttle.

Bi-directionaly throttle sounds very fun and they aren't commercial available. I can design good gear for a 3D printer, If the circuitry is easy I can design one.

I'll have to read again, I'm not clear if the bidirectional requires ebrake engagement at the the same time...
 
Or just:
Using the brake cut-off on the controller will apply a baseline 20% regen torque which can be increased by varying the throttle between 1.0V-3.5V while braking.
which means you engage the ebrake lever (or switch) and then use the throttle to vary the braking force from 20% at throttle off on up to (presumably) 100% at full throttle.


Either method works according to that page.
 
That's why I hoped my bike had ok voltage for it, It can do precisely that, Indeed Justin has told me that is only for CA3.

Perhaps it will give me a chance to design a 3D printer tweakable bi-directional throttle...

I have some spare twist throttles at home. perhaps I should copy one to keep the same hall effect chip and spring and have a .8 to 0 function and a rest zone fine tuning bolt, it might take just a day.

A switch / a variable resistor on the throttle voltage would also technically be usable.
 
zzoing said:
I have CA23. CA3 is necessary to configure a base ebrake resistance setting. Do I need CA3 for variable regen?

Can I arrange variable regen using CA23, throttle and Grinfineon 2018 48v 40A controller? How do I do it?
Nope - the CA3 is not required.

As the manual excerpt above details, the Grinfineon (and Phaserunner) controllers have a dual regen capability that is unique to Grin controllers.

  1. The first mode increases regen when you increase the throttle with the brakes applied. This mode is designed to work without any CA or special hardware and uses the normal throttle voltage range (1.0V-3.5V).
  2. The second mode only works without the ebrakes applied and uses a special 0.8V to 0.0V range of voltages to increase regen. This second mode is designed specifically for the CA3.

zzoing said:
When I engage the ebrake, does it switch the throttle line to 0.0V? Does it stay at 0.8V? the ebrake is not a simple switch?
The ebrake is a simple switch and does not affect the throttle voltage at all. As outlined in the two cases above, it does determine which throttle mode is used for variable regen.

zzoing said:
I thought that It would give me variable regen right out of the box, perhaps I have to program the controller differently? It's not switched on to variable mode?

Good question. The Grinfineon controller is actually not programmable. The two regen modes are mutually exclusive according to whether or not you use the ebrakes and should work right out of the box.

zzoing said:
I asked Justin who said:

You will require either a throttle that is bidirectional and has a 0.8-0.0V region for regen control, or the use of a CA3 device which will be able to output such a throttle voltage based on a normal ebrake lever and the regular forwards throttle.

This is very confusing. I do not believe that they have removed the normal mode that uses ebrakes. I'm wondering if your question was about variable regen without ebrakes (?). That would make his remark make sense.

I'm going to put that remark aside for a minute and plow along with the way I understand they are still shipping those controllers (according to the manual excerpt above)....

zzoing said:
there are 15% hills everywhere here.

I think what is happening is that your CA2 is preventing regen because you may have a speed limit set and are exceeding that limit in your regen test. If that were to occur, the CA would try to slow the motor by reducing the throttle voltage. Since you are on a hill and reducing motor power is ineffective at slowing you down, the CA keeps cranking down the throttle in a futile attempt to slow down. Pretty quickly it gets to minimum or about 1.0V. This would stop the motor completely if it weren't already stopped by the ebrakes but also clamps the throttle so that you cannot apply regen. Oops.

Here you are getting into a little trouble because the CA2 does not know about ebrakes or regen and is blindly doing its motor thing. The CA3 does know about those and so behaves more appropriately.

So - to test this out, either raise your speed limit to maximum or try your regen test with the CA2 unplugged. Either strategy will prevent the CA from affecting your throttle and upsetting your attempt to control regen. I'm pretty sure this will fix the issue - anyhow it's a best guess :D

  • FWIW:
    Although you should not require a CA3 to make the basic variable regen work, the CA3 does have some nice regen features. For instance, you can hook up a pot or a two button (up/down) DigiAux switch and configure the CA3 for regen speed control and speed adjustment by the pot or DigiAux. Now on hills the CA3 will automagically slow you using regen to whatever speed you have dialed in - no ebrakes required. You just ride along and back off the throttle on a hill and the CA does the braking. You can twiddle the speed knob on the fly if you wish, and of course you can use the ebrakes to override this automatic operation. Kind of handy if you live in the land of hills...
 
That CA3 option is pretty awesome, it would indeed be good. thanks for your advice, I ran a test setup without CA23 plugged in, and I added a switch to send the throttle to 0V to see if there's a difference.

Without CA23 I am having the same, 50% regen, with throttle range 0.8v to 3.5V I don't notice a difference.
If I use a switch on the black throttle wire to have 0V, the regen LED signal also appears, but there is no regen felt in the wheel. Actioning ebrake and 0V is 50% same as with a throttle. .

I thought this was a fairly easy question, sorry it's getting a bit too complex for the forum. I'll have to seek advice from the the designer.

The document confirms the quote:
http://www.ebikes.ca/documents/Grinfineon_V2.1.pdf section 3.4 and 3.5
The Grinfineon controllers have regenerative braking capabilities, allowing you to
use the hub motor as a brake and return kinetic energy back into the battery
pack. This can be achieved either with the ebrake lever for a constant 50%
braking force, or with a 0.0 to 0.8V throttle signal for variable 0-100% braking.
 
zzoing said:
I ran a test setup without CA23 plugged in...

I'm still getting a good, unvarying regen, actioning the ebrake, putting the throttle to max, else switching it to 0V, the bike cruises downhill totally regular speed,
I had emailed JLE about this and he pointed out that the mode using ebrakes + (1.0V to 3.5V) throttle was lost when the controllers went sinusoidal. Apparently there was a restriction in the chip with the added sine output change and some things had to go - Grin didn't want it to happen, but the hall auto mapping and one regen mode got squeezed out...

The change was noted here:

JLE said:
3) While we still have proportional / variable regen from a 0.0 to 0.7V throttle signal for use with a V3 Cycle Analyst, the regen from an external ebrake input is fixed at 50% of max. It does not change with application of the throttle voltage

The Grinfineon controller manual was updated as well - section 3.3 no longer discusses the ebrakes + (1.0V-3.5V) throttle mode. I pinged him about the words left on the Grinfineon web page - that description seems to have slipped by the update.

  • EDIT: Grinfineon web page has been corrected - sorry about the confusion.

So - that makes his remarks above make perfect sense and explains why my CA-is-clamping-the-output theory is incorrect - that mode doesn't exist any longer - only the (0.7V-0.0V) throttle mode for the CA3 remains.

There's still a mystery about your 0V experiment, but some of this is clearing up....


FWIW - here's a plot from the CA3 Guide that shows the expected regen + throttle response. You can ignore the "ThrO->xxx" text on the left - those are CA3 settings to tune the throttle operation, but the general controller voltage range and behavior has nothing to do with the CA3 per se.


 
zzoing said:
Without CA23 I am having the same, 50% regen, with throttle range 0.8v to 3.5V I don't notice a difference.
If I use a switch on the black throttle wire to have 0V, the regen LED signal also appears, but there is no regen felt in the wheel. Actioning ebrake and 0V is 50% same as with a throttle. .

Thanks for starting this thread zzoing!

I have the 35A Sinewave Grinfineon, and also would like to be able to have 100% regen without the CA3. I have 15% grades both ways on the commute and the regen works/is really great even at just 50% with the ebrake--100% would be wonderful.

Has anyone gotten 100% regen without a CA on the latest Grinfineon ? I am guessing the test zzoing did was to short the hall signal to ground--maybe the swing in V is too rapid and the absence of a ramp is the wrong signal for the controller.
 
I have had some advice about how to do so from Justin, alot happening:

... this is pretty interesting. It could be that you need to actually short the throttle signal wire of the 6-pin CA plug to Gnd instead of the actual throttle wire, as the throttle input on the controller has a mix of pull-up - pull down resistors to force it to rest at 1.0V and this might be messing things up a bit. So yeah, see what happens if you hook up the short circuit button for the ebrake to the green wire on the CA plug.
 
So, that's the most technically savvy info from this page from Justin, it's a development surprise with the current Grinfineon which means that fwd/rev throttle can't be implemented through simple wires of the ebrake, only via CA3, and by the different wire schema described above.

I haven't had the motivation to check it because the ebrake is already very satisfactory and I the bike and grinfineon is awesome so I ran out of motivation to mod it for variable hub regen. It's good to have the info available to adapt regen.
 
A simple and robust two way throttle would be ideal. This has been discussed elsewhere IIRC on the forum.

I am going to wire one e-brake (cheap ones that came with some WE kits a long time ago) to the normal e-brake input on the controller, and wire the other one to the throttle signal on the CA plug on the controller, and see what happens. Try out the combinations on a nice quiet hill with no traffic. I will report back on that. Maybe they will work as expected: e-brake to e-brake input = 50%, e-brake to CA plug throttle = 100%, both e-brakes on = 100%? If this works, put a variable resistor in line with the CA plug circuit, trial and error, maybe get adjustable regen.

Thanks!
 
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