350htrr

But you guys are missing the fact that I wasn't pedaling while in re-gen... I also had the E-Assist in level 4 all the time I wasn't using re-gen going up the hill and level 1 on "flat" roads which means that there was a measured amount of E-Assist all the time from the PAS, the same for all the tests, there was no "free pedaling"... I also have some numbers for when I was using the re-gen but I don't really know the math to make sence other then I know there is power going back into the battery... I don't know what 40Wh for 12 minutes equates to which is what the re-gen was putting into the battery, and I don't know what that wattage would be good for in extra distance, so I used volts as the baseline as to what I started with and finished with for all the runs and the volts used from the battery was always a lot less when I used the re-gen, sssooo that says to me that re-gen works well... The BionX meter is very accurate, it's basically a computer that measures everything volts,watts going in & out of battery, amps used... Thus I'm very confident that the volt numbers are accurate...

EDIT; Because I was using the PAS all the time, I was in E-Assist for the whole time, even tho I was pedaling and wasn't using the throttle only method of testing, there was a measured amount of power used all the time...

EDIT 2: Yes I understand that any kind of pedaling without using the E-Assist would skew the numbers... But I never pedaled "free" I used the PAS all the time, thus all the KMs were under measured power assist...

SpecialX

Correct, If your only using the PAS then you won't get any true regen numbers...
Why not try with throttle only and see what you get?
Does the bionix computer give you WH used or any other information like that?
That is the only way you will be able to see your exact regen numbers.
Given my earlier examples, you can see how badly skewed regen numbers can be while pedaling.
If the bionix computer doesn't have Wh usage, then the only way you can really tell is by doing a no pedaling, ride till the battery is used up, and recharge and do the exact same trip again and see how much farther you get.
There really is no other way, other than getting a unit that computes regen Wh put back into the system. (Again, remember, no pedaling allowed!).

Until you can either do the trip I suggested or get a unit that computes regen numbers, there really is no point in arguing how much regen a system gives you, as the answer will never be true numbers and you can conjecture until the cows come home.

Btw, what voltage / AH is the battery you are using?

I'm using a 48v 30ah battery, on a rear wheel setup, myself.
(I have a very heavy bike, otherwise, I would get a lot more than 60 Miles on a charge. I'm also about to setup a second motor / battery (36v 12ah) for the front wheel to extend my range even further.. I'm expecting another 15-20 mile avg distance extension - I'm planning on using the front motor (in conjunction with the rear motor) for take off from a start until I hit 16-18 mph and then "cruise" using the rear motor alone).

Edit: While you state you're getting 30ish something percent regen, it IS true, but that's NOT regen from the motor, that's regen from the motor AND YOU! I would estimate, that you are adding about 25ish percent of the regen in your pedaling. Again, realize that you must use a "fair" example by not only going on a mostly downhill route, UNLESS you go the exact opposite route (mostly uphill) for the second part of the test.

350htrr

I can see the re-gen Wh numbers as it happens, it shows 40Wh downhill for 12 minutes. No totals show.
I can see the Wh numbers as I use them, it shows 35Wh up hill for 29.5 minutes. No totals show.
I did not pedal at all for re-gen, coasted down the hill...
I have a 48v 8.8Ah battery 350v motor.
MY 34.1% re-gen numbers are totally pedal free coasting downhill 51KM/Hr in post 66, and 38.3% pedaling to keep up normal downhill speed 50KM/Hr in post 33 ...

SpecialX

If what you say is correct, then 40wh for 12 minutes is only 8wh gained...
I see now where your logic is flawed..
A watt-hour is exactly that, watts per hour... (You said it's giving you instantaneous numbers (a WH is not an "instantaneous" number, it's power over time))

40w for an hour is 8wh in 12 minutes (1/5th of an hour)
So going downhill (for that 12 minutes) put back in 8wh, which is perfectly reasonable.
Most regen numbers are between 3-5% on flats, and 5-10% on downhills..

350htrr

Well I'm probably wrong with the W, WH thing, Need to find out from BionX what those numbers mean for sure... But the voltage at the start and the voltage at the end of the ride numbers are correct for sure...

SpecialX

On your battery, in my experience, I would estimate that you should be able to get at least 20 miles (33 KM) distance capability on motor (throttle) power alone.
(I know bionx says, you're supposed to get 100 km (assist level 1) on the battery, but in real life that's not gonna happen on 8.8ah 48v (432 wh) unless you're only 100lbs and the kit is on a recumbant bicycle that's really light, with the wind behind you, going downhill 90% of the time.)

If you have time, you should try my experiment and run battery down to empty without using any regen (or pedaling) and then try again (same route) with regen (no pedaling) and see what the mileage difference is.

What information (totals) does the bionx computer give you at "the end of your ride"?

rscamp

Good catch, SpecialX. Watt-hours are cumulative. Although a Watt-Hour is a measure of energy and is the product of Watts X hours rather than Watts per hour.

350htrr - Can you take a close up picture of your screen so we can see what it is showing?

350htrr

Well that is what I will have to do I guess, to get things straitened out in my own mind, re-do with just the trottle... For the average guy they are just giving basic info, I managed to get he code for the diagnostics screen but no documentation to explain anything (it's a big secret)... That's empty when it says empty? or empty till it won't move and shuts off?

SpecialX

Here are some pics of my bike, for those that are interested....










g





Questions? Comments? Queries?

I have all the amenities....

P.S. I am in the middle of re-wiring it, as I have purchased another one like mine and will be exchanging parts around....
The complete new bike will have two motors, two sets of batteries for the motors, and all the wiring will be installed within the main tube, so you can't see them.

Here is a pic of what the bicycle looked like before I changed it all around. (Also a pic of the "spare part" bicycle I'm using to complete my build.

350htrr

It shows big numbers that I think is watt's used under power or watts generated in re-gen (centre of screen) and 5 numbers bottom right of screen first two show PAS effort and last three numbers show voltage, left four bars re-gen right four bars assist, centre bars battery state...

SpecialX

Well if it says "empty", I would guess that it's completely empty and won't move.... but COMPLETELY empty would be a complete power down... (make sure that the computer, has the ability to show you km ridden after the battery shuts down)...

Can you pedal the bicycle easily enough without the motor?
Maybe, your "trip" should keep you close to home, if you feel that it might be a problem riding back without power.
And of course, it's gonna take some time to recharge back to full.
It will probably be an "all day test", but try it on mine with a 60 mile range, and it's REALLY an all day test. (It takes 5 hours for me to recharge from dead to full)

350htrr

Pedaling without the motor on is no problem, just like a normal bike...

rscamp

Wow. This is a wild goose chase. You appear to be in diagnostic mode. It could be the large numbers are displaying something like the strain gauge value for pedelec assist. You need to look up the documentation for your system and find out!

You should disregard this value until you know what it is.

350htrr

The first two small numbers are the strain gauge 0.0 for sure just like the last tree numbers are voltage 51.4v.

SpecialX

Its easiest just to do a mileage test, with and without regen....
That will give us a definitive answer as to how much added distance he gets with regen.
I'm pretty sure that the bionx computer doesn't give WH, AH, or any other really useful information, but who knows..
I still have to order a Cycle Analyst or other Watt Meter (Probably a Turnigy model, since it's like $30 compared to the CA price of $150)

rscamp

Quite the contraption! Does it have a refrigerator?

Here's some info on a trike I ride:

https://www.flickr.com/photos/rscamp...7635549406106/

SpecialX

With my 12v 90Ah battery and 1200 watt inverter, I CAN run a small fridge.
With the 12v battery, I've even charged up my boss' Bobcat... and also jump started a truck.
I have built in a 1.0a and 2.0a 12v-5v USB charger, for my Iphone and Ipad. Also has a cigarette lighter and 12v port. (as shown in pic)

chvid

What about total watt hours expended - minus watt hours gained in regen over some course, run twice, once with regen and once without regen, in such a fashion that the average speed over the same course was identical in each case. Would'nt the regen slow the bike down enough that yes, it would be more efficient, but that would be expected anyway, because you are going at a slower pace (which uses less watt hours (energy) per mile anyway whether regen is used or not). When you then adjust back to the higher average speed for the regen case, I doubt it would be favourable. I guess its ok if you don't mind slowing down on big hills from the regen resistance to get the energy back, but couldn't you have got that anyway by slowing down? If you want to get there faster, and at the same pace using regen, then does regen get you anywhere? Because you need to expend more energy to offset the regen resistance to maintain that average speed. I guess its better in stop and go riding. At least that's what Justin at ebikes.ca indicates - 5-15% improvement in stop and go scenarios like Vancouver. I generally don't want to sacrifice any downhill speed just so my brake pads will be happy - if I need to use them were I coasting through the valley, and I could get a bit back. if I want to maintain my speed down the hill to simply coast up the other side of the valley, regen isn't going to help me much - if I need to keep my speed up. Why put the energy back in, when I will then have to use more of it just to get up the next hill because my speed has gone down. All that potential energy in your vehicle sitting on top of a hill can help you get up the next hill whether you put it back in the battery - just to expend more of it due to lack of coast, or not. So you're not really saving your brakes either - if you're using them on a hill where there is no stop at the bottom of the hill and you wouldn't use them. I only use my brakes when I stop, not when I go down hills in the regen case. So if there's a lot stop and go, I can see the benefit, but not in hilly terrain so much without much stopping where you want to keep your speed up (unless you happen to be hardcore eco-miling for very long range - but that involves very slow riding in either regen or non-regen scenario).

chvid

Almost - but only if both scenarios have exactly the same average speed over the course...hard to test this as that test condition is hard to set, given the regen drag. Need to offset regen slowdowns with non-regen higher speed energy bursts using more energy. The regen drag will save your brakes, but you will often be braking from higher speeds in the regen scenario, given your need to keep your average speed up to match the non-regen scenario. That's gonna give you more brake wear, because of the high speed stops.

chvid

I think with regen you are using your brakes more often when normally you wouldn't be using them at all! I don't see how that translates into reduced brake wear, unless you like to have average speeds which are slower, which could very well be so. To me, its about getting there at the same pace - does it help then - as opposed to just introducing more "frictional losses" in a thermodynamic sense.

350htrr

I suspect you would never be able to keep the same speed on a course using re-gen as compared to not using re-gen. I topped out at 51KM/Hr compared to 69KM/Hr without re-gen, same hill.
You end up loosing some speed to gain distance... I also do not need to use the brakes for re-gen, the BionX allows for it by picking re-gen levels separately 1 to 4...

SpecialX

You're gonna confuse the poor guy....
Forget "average speed", wear and tear on brakes, etc .....
No matter what, it's not going to be the EXACT same average speed over the course of his test... Especially, if there will be stop lights, other vehicles in the way, etc.... (there will ALWAYS be variables, that you can't use as part of a "controlled test"), but it will be a good enough to see what kind of range extension his regen gives him...
Whether he uses his hand brakes or regen from the motor, won't have that much of an adverse effect on the numbers. Too much confusion added to a fairly simple test, when considering average speed... there's also, wind, tire pressure, weather effects, etc..
The point is, given my experience, I forsee that the regen numbers will ultimately come out a lot less then 30ish percent....
I would be completely amazed to see even 15-20 percent... I would expect, somewhere between 10-15% as a best case scenario... and probably closer to 5% in real world conditions...

Also, I suspect that the bionx computer doesn't have the ability to show the WH used, AH used, watts being used, watts (and/or WH) put back via regen, etc. ("usage numbers")

IF it did, then all he would have to do is run the bike, throttle only (no pedaling) and just run until the battery died and then see the WH put back in via regen.... then divide the total WH available (in his case 423wh) by the regen WH he got back... wouldn't matter if there is wind or no wind, or stops and gos, or anything else... AND If it's the same ride he does every day, he could repeat the process, a number of times and take the average of those.

EDIT: I've looked around as best I could and there is apparently, no settings you can edit on the bionx computer, that will show you any "usage numbers"... If there is, I couldn't find it...

His only way to do it is either a watt meter addition or his "run test".

chvid

I agree with you on the 5% improvement - and I suspect a lot of that would be due to going slower on average, over the course of the trip. If I'm freewheeling down a big hill and I'm at 30mph at the bottom, that's going to carry me probably just as far up the other side as all that saved regen energy that I now would need to use to get to that same point on the other side, considering that I'm moving a lot slower at the bottom, in the regen scenario with not much follow-through coast. My trike has a lot of kinetic energy at the bottom of most hills - the ones I don't need to stop at. 100 lbs of trike and battery going 30mph is a lot of kinetic energy. I don't want to bleed that off into my battery just because it sounds scientific...I want to use it directly to get up the next hill with the coast.

So, range extension for some number of watt hours expended doesn't tell you anything interesting. I get range extension all the time with no regen just by travelling more slowly to use X watt hours. Range extension - at the same average speed for some meaningful duration like the whole trip - is what we should be interested in.

For example: I go 50 miles and average 15 watt hours per mile, and my average speed is 20mph over the 50 miles. Vs Regen case... I go 50 miles and my average speed is 20mph and my average watt hours per mile is 13. That's a real improvement, if you could get that much, which I doubt. I imagine you'd probably get around 15 or possibly worse in the regen case. To offset the regen slowdown on non-stop-at-bottom hills, you'd have to ride more in the faster high-aero-resistance zone than in the non-regen situation, which is very inefficient, say over 25mph.

I think the jury is still out for average recreational riding - and there is the additional complexity and cost factor with regen... I guess I just like coasting.

SpecialX

It really depends on if you have a hill to go up after a big downhill...
There's always a million possible variables....
The range extension, is just to find out what his average percentage of regen gain is. (for his particular instances of environment variables.)
That way, he can then also say, what his worst case scenario for his max range is..

I know my worst case scenario on my bike is 42.3 miles.. (That's the least mileage I got, when I had an extra 100lbs (45.5kilos) on my bike and rode from my old house to my new house going pretty much WOT the entire time - Avg speed ~22mph (37kmph)... I had a couple of small hills to go up.)

When I add my second motor and battery (prolly 36v/12ah) I'm gonna see what my new Best case scenario will be.... I'm guessing somewhere in the 90 Mile (150km) range....
My average mileage, should be around 80 miles/130km (Up from 60miles/100km) and my worst case scenario will probably be 60miles.

My average consumption is around 20 wh/mile.

BTW, I had to change out a controller that went bad about 2 weeks ago, and I don't currently have regen....
BUT I do have 2 brand new controllers with REGEN just waiting to be put in, when I get my new battery for my new motor..
In the mean time, I'm going to purchase a Turnigy Watt Meter for the rear motor/battery setup that I currently have, so I can test the exact WH capacity of my new 48V 30ah battery. (I may have to purchase a second one too for the front motor/battery setup, but I don't know if I will have enough real estate on my handlebars/center console.)


Also, You're on a recumbant, aren't you.. completely different wh/m (or KM) usages..

rscamp

But the question is what are the big numbers showing.