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View Full Version : Jack Richard's tests indicate NO RANGE INCREASE with REGEN controllers



NonPolluter
29 September 2010, 1937
Overall, Jack's exhaustive tests can, in my opinion, be taken as gospel.

However, I want hard regen braking because it saves brake pad wear and reduces reaction time, making for a much, much safer ride.

There is also the increased safety of having two brake systems --- Failsafe in practice.

The EMS crew should be complemented for the super hard regen on the Native Z6 which, properly triggered, does 99% of braking. (You still need to use the handlebar brakes to trigger the brake light, as a warning to drivers behind you.)

frodus
30 September 2010, 1331
Maybe not with his setup. Haven't seen his videos (nor will I watch them because he's been an asshole to everyone who disagrees with him), but I question the "control" in his experements and the methods of measurement.

Before when I saw his testing there was so much room for error that he could have easily tilted things in whichever direction he wanted to. In fact, he actually has contradicted himself several times and has eaten his words on the forums.

Taking it as gospel is fine, but he's MUCH newer at this than most people realize, and he has only a handful of followers.

teddillard
30 September 2010, 1338
>>biting tongue. don't say anything about tinfoil hats. nope. don't go there. <<

oh wait, did i just say that out loud? :D

HighlanderMWC
30 September 2010, 1352
However, I want hard regen braking because it saves brake pad wear and reduces reaction time, making for a much, much safer ride.

How does regen reduce reaction time?

frodus
30 September 2010, 1419
>>biting tongue. don't say anything about tinfoil hats. nope. don't go there. <<

oh wait, did i just say that out loud? :D

haha.

Touche

DaveAK
01 October 2010, 1348
Maybe he's doing it wrong.

Richard230
01 October 2010, 1448
The regen in my GPR-S adds about 3.5% to my range during a typical ride - according to the Ah usage compiled by my Cycle Analyst.

billmi
02 October 2010, 1136
How does regen reduce reaction time?

Who cares, if it reduces brake pad wear. Better to put wear on your drive train instead, since it's so much less expensive and easier to change than brake pads, right?

teddillard
02 October 2010, 1332
Who cares, if it reduces brake pad wear. Better to put wear on your drive train instead, since it's so much less expensive and easier to change than brake pads, right?

can't believe you got me on that one... i had a couple of paragraphs all ready to rip. :p

jazclrint
03 October 2010, 2230
How does regen reduce reaction time?

To answer you question . . .

I look at regen like engine braking. As soon as you roll off the throttle the bike will start slowing down. There is sometimes a delay, albeit a second (give or take) from when you start rolling off the throttle until you grab the front brake lever. What happens on an ICE bike (like my '91 Honda VFR750F) is as I close the throttle the engine braking starts almost immediately slowing the bike down in the time it takes to reach the lever.

However, here's the problem with some of what's been said. It's been said by either people who don't ride motorcycles, or who need to learn. Regen braking, or engine braking are convenient forms of braking that can make life easier. But in both cases, regen braking happens with the rear wheel which only produces 30%ish of the braking power. Also, there is a lever at your foot that you should be able press the split second or sooner from rolling off the throttle. Not to mention, you should have you controls set so that you can reach the front brake lever and start squeezing as you are rolling off the throttle. Then there's the saving of brake pads? Motorcycle brake pads are not that expensive for everyday compunds. Sticky compounds are another story.

And lets not forget that 2-stoke motors have little to no engine braking, and they were the engines of choice in the highest forms of motorcycle racing for the past 60+ years. Those riders coped just fine. As a matter of fact, the slipper clutch (which reduces engine braking) was introduced to 4-stroke racing bikes because the engine braking got so powerful in relation to the speeds they were entering corners.

DaveAK
03 October 2010, 2240
If you're concerned about reaction time then ride with two fingers on the brake lever like I do. It doesn't need to be any more than that. Engine braking, (for me at least), is only for slowing down in the normal scheme of things, (coming up to a junction, etc.). God gave us asbestos when we need to do things in a hurry. (Or what ever non-carcinogen they use nowadays.)

In my opinion if you're concerned about reaction times and you're rolling off the throttle and then applying the brakes you're dead meat.

teddillard
04 October 2010, 0327
The regen in my GPR-S adds about 3.5% to my range during a typical ride - according to the Ah usage compiled by my Cycle Analyst.

Thanks, Richard. This is the only actual experience/data I've read about regen. Opinions and conjecture are swell, but it's nice to see some fact. I'd love to see some more detailed observation over the course of different riding conditions, you think that would be possible to put together?

Richard230
04 October 2010, 0804
I might add that amount of regen on my motorcycle only amounts to an extra mile of maximum range - at most (and that assumes that you do a lot of downhill riding). I would have to say that the extra cost of the equipment and the resulting slight additional weight and complexity is not really worth this small range increase. However, the feeling of the regen activating when braking and the resulting bragging rights is kind of cool.

From a practical view, I believe that regen is not worth the money. But it might be more valuable in a heavier vehicle like a car - especially one that has a gas engine to get you up a long hill and regen to recharge your batteries down the hill. I have been on plenty of long downhill highways in the Serra Nevada Mountains where you could probably recharge an entire battery pack while going downhill from the top of an 8000 foot high pass to the lowlands. If nothing else it would help keep your brakes cooler if you were driving a car or truck. Anyone for a hybrid motor home?

frodus
04 October 2010, 0840
but if regen is FREE, why not use it?

Most of the vehicles that I see talked about, are Cars and Trucks using AC or BLDC motors, so its kinda built into the controller.

DaveAK
04 October 2010, 1021
Thanks, Richard. This is the only actual experience/data I've read about regen. Opinions and conjecture are swell, but it's nice to see some fact. I'd love to see some more detailed observation over the course of different riding conditions, you think that would be possible to put together?
I've seen similar figures quoted. To have Richard actually state his observations, and for them to fall in line with what I've read elsewhere is good enough for me.

Richard230
04 October 2010, 1521
Frodus is correct, regen is free - but only once you have it. On my bike it was a $1300 upgrade, which included a different controller and the D&D motor, compared with the "stock" production 72 V GPR-S. Still, I do like the way it makes the motorcycle feel more like an IC motorcycle's compression drag when decelerating. Without regen, you are coasting and depending entirely upon your brakes for slowing down. Nothing wrong there, but it can feel a little odd and a bit scary if you are used to IC motorcycles like I am.

Here is another real world example comparing apples to pears, if not apples to apples: I rode both my 2008 60 V, 20 cell, 50 Ah Hi Power battery pack, GPR-S without regen and my 2009 72 V, 24-cell, 50 Ah Hi Power battery pack, GPR-S with regen to work over the exact same route and distance and speeds. Due to its larger motor and additional 4 cells, the 2009 bike with regen weighs about 40 pounds more than the 2008 bike and draws slightly less current due to battery voltage sag under load. Commuting the 10 miles to work would typically use 15 Ah while riding the 2008 GPR-S and 13 Ah while riding the 2009 GPR-S with its regen system. I believe this is due to the Cycle Analyst subtracting Ah generated while riding downhill. The total Ah used would be less at the bottom of a hill that it was at the top of the hill. Whether the fewer Ah used during my commute were due to the lower draw under load or to the contribution of the regen is debatable. My guess is that both are a factor.

Whether or not this represents real usable power replaced in the battery pack, or just a number generated by the CA, I have no idea.

frodus
04 October 2010, 1527
Its a completely different system for you though Richard, its apples and oranges. Going from Brushed to Brushless is a big step in price, so no, its not free.....

My statement has more to do with Jacktards argument about it not doing anything...... he's using an AC Induction motor/controller..... why not just use regen? He gets it for FREE. Its the same cost for him whether he wants regen or not.


I personally want to see someone actually measure the Ah in and out of a battery pack with lab equipment. if you go over a route, and you actually put ANY energy back into the pack, there is a benefit!

Richard230
04 October 2010, 1543
Good point, Frodus. Of course I have no experience with AC motors and what you say about someone needing to accurately measure the advantage of regen scientifically is certainly true. I can only provide my seat-of-the-pants experience with my bikes and my observation of their Cycle Analyst display - and I have no idea how accurate that display is. One thing I know for sure that its speed readout is not accurate on my 2009 GPR-S.

frodus
04 October 2010, 1601
yeah, I'm not sure its that accurate.

I just don't really "bite" at Jack's opinion towards a lot of things.

BaldBruce
04 October 2010, 2112
Jacktards argument about it not doing anything

Thank you Travis, I needed that laugh.:D

electrician
05 October 2010, 0700
I found this quote on the "Lectra" web page: "In general, coasting to a stop is much better for increasing vehicle range than using regen braking."

seanece
05 October 2010, 0738
frodus

but if regen is FREE, why not use it?


Exactly!!! :D

I hope we are all taking into account normal driving conditions. Coasting to a stop and accelerating from 0-60mph (in 10 minutes) will definitely save energy, but neither are practical on today's roads. It is a fact that we make quick stops and we accelerate fast. And trust me, I love an electric vehicle that can peel away from the ICE crowd, I think that is cool as hell!

Regen is a very good thing for vehicles. But please note, there are some cons.....
- If you cannot appropriately cool your motor, the regen will FURTHER heat up the motor causing all sorts of neat epoxy smells
- Your batteries may not be able to get recharged at given Regen C-rate
- You will never, NEVER recover as much energy as you used to accelerate

Regen is a great feature otherwise...... if used properly to recover some energy (especially on vehicle that can run 80+miles on a charge). Let me install some current sensors and a DAQ on anyone's vehicle sometime. With practical data in Excel format, you will see how your system recovers otherwise lost energy if you are driving normally. My best example for Regen is "engine braking" with an ICE - You can use your brakes, but why do that if you need to shift anyways and slow your ICE RPM down. Plus, with electric you can recover some energy!

There is nothing wrong with motors and controllers that can Regen. Regen can be a good thing and should not be shunned. As motorcycles go further and further on one charge, regen capabilities will become more obvious and "tangible".

My 2 cents, for what it is worth.

P.S. My Curtis setup is simple and to the point when it comes to regen. The features available with the controller are amazing and you can tweak any setting you want. Now, regen on the race track is a completely different story. Much more weight is "slammed" onto the front wheel than the back and regen is less of an issue. If Chip Yates can ever get his vehicle functioning (without noticable unsprung weight) then his idea may be a game-changer on the track and off.

jazclrint
05 October 2010, 0812
Chip Yates? The love child of Chip Ganassi and Arron Yates? :D

Seriously though, I have no idea who Chip Yates is.

frodus
05 October 2010, 0835
http://lmgtfy.com/?q=chip+yates

:)