harvests momentum to recharge batteries/capacitors

[liveforphysics]

Hi Luke,

I'm very interested in your comparison above between LiPo and supercaps. Sure, if the total energy is a major consideration then a battery is best, and, yes, the varying voltage on the cap can be a problem.

But the varying voltage can be overcome, or even exploited. What about the situation when you only want to store a small amount of energy for a short time, but the rate of storing and delivery is important. I'm thinking of storing energy when you go into a corner and then delivering it back when you accelerate away again. Does the supercap win out then?

Nick

With LiPo cells factory rated for continous 5C charge, and easily bursted to 10C charge, I think you will find that with minimal volume and mass of LiPo, you reach that tire traction limit of how much power you can regen before the braking stoppies or the tire slips. It would be reasonable to give over 1kw/Kg of burst regen ability for good, yet still cheap HC 30-40c LiPo. A monster front wheel regen setup on a long bike with a low COG could have some pretty high maximum regen energy limits, but even then, I doubt you would be seeing more than 5-10kw or so at the most in the very best of situations.

Most all of the supercaps have higher Ri than high C LiPo cells, which means they're going to be wasting more of the regen and discharge energy in heat than using similar size/weight LiPo cells would be doing, and you've gotta deal with some sort of switching variable input PS setup to be making use of a decent amount of the energy in the caps due to the non-fixed voltage.

Even just to stiffen a LiPo battery with supercaps, you're still going to end up with better charge/discharge rate performance by using that same space/weight/money to just add more LiPo. The small caps have high Ri's and end up useless energy storage, the big caps that get the Ri's down to LiPo cell levels would still give a lower Ri pack if there volume/weight were replaced with more LiPo, not to mention loads more energy storage.

 

[Tiberius]

Thanks Luke, it sounds like the Ri on the supercaps rules them out. The application I'm thinking of needs to deliver 5 kW or so in bursts of 10 secs. It may be that I can charge at a lower rate so LiPo would work. Even so, by the time I've got enough capacity to deliver 5 kW, it will run for way over 10 secs, which is why I was thinking of caps.

I agree about stiffening batteries with supercaps. It just doesn't make sense. You can only exploit a tiny fraction of the caps storage.

Nick

 

[Momentous]

charging a booster pack
placed after the controller output, initial draw of starting from a stop on the main riding battery pack would be less.
probably using a better suited motor than the one is being used would help

Dont batteries absorb current in proportion to their capacity .. and maybe a high draining cap would be helping

Myzter push on Are you using both ?

 

[liveforphysics]

5kw of regen on a 26" tire at 20mph (~250rpm) would be 141ft-lbs of torque, and on the 26" wheel, it would be 131.15lbs of force slowing you down. I would say that solidly puts it in front-tire only territory, and you'll need to be careful about keeping the COG low and far back, or it's going to flip over on it's nose. This is assuming a 100% efficient kinetic to electrical conversion as well. I think realistically in the above example it would be more like ~170lbs if you're getting 5kw of regen off the wheel. If the weight of the bike and you are say 250lbs, this means 0.68g's. Draw your little force diagram, and you better make sure that COG isn't higher than 1.47 (1/0.68) times the horizontal distance from the front tire contact patch to the horizontal center of mass location, or she's gonna flip. I think this would rule-out most every traditional road-racing bicycle style frame geometry. I think recumbent style bikes would handle it fine though.

Best Wishes,
-Luke

 

[Arlo1]

Myster.
It realy seems that you are trying to achive perpetual motion. Are you trying to build a setup that charges more then it uses? are you trying to charge as much as you use in terms of power? Luke has a very complex way of explaining it. But the best you can achive would be <100 percent eficent meening you can try to get 100% and as this whole electric revalution continues we will get very close but we WILL ALWAYS NEED A SOURCE OF ENERGY which starts from the sun. So my therory is lets focus on that. Lets get power strait from the sun and try not to waste it ( well I might be bad for wasting it but there is alot of slower ridders who will make up for me lol) So you can do this if you want, install solar power on you bike or make a solar charging system at home and power it will that. Something on the bike will likely not produce enough for you to knotice a difference but if you like I have a link I can send a calculator for watts per sq foot and other factors table to design a solar system. The coolest number I keep hearing scientest say is in one Hour then sun floods the earth with enough energy for all of man kinds needs for a whole year!
In the end the most efecint you can make your bike will be with a simple brushless motor and keep it cool as well only use rengen to slow down and not anyother brakes. Some have found 2 wheel drive to be more efecient in some cases but only because it helps each motor stay cool. Adding another motor to be always regenerating power will increase the load on the first motor and all you will do is waste power in terms of heat! Good luck with your work and I am an optimast but just know enouh about physics to not try to achive more then 100%

 

[Jeremy Harris]

I'm glad you raised the perpetual motion point, Arlo, as I'd been thinking it for some time, but being British, I was trying to be polite and not raise it.....

Jeremy

PS: I see you're from Nanaimo. Despite being a Brit I've spent a lot of time there, working out at CFMETR back in the mid-90's. I'm reminded of it right now, because we're having some pretty damned cold weather here in the UK, cold enough for me to get out a rabbit fur hat I bought in Nanaimo fifteen years ago.

 

[myzter]

Hi liveforphysics
yep you got that right, this bike likes to flip as it is..
The last bit of generator rpm the cogging kicks back in, and zero watts are absorbed by the battery

are you trying to charge as much as you use in terms of power

not quite Arlo1, Im trying to capture that initial energy thats used to move the bike

the mechanical losses in the power train and electrical losses when the ac current is rectified do push the overall system efficiency down to the lowest of 50%.

Ofcourse a different motor than my Currie is needed for sure M.

 

[liveforphysics]

Myzter- I would highly recommend at least a Jr. High level beginner physics course. There are lots of them available online that play in a browser, and you can click for a new slide as needed at your own pace. You could just skip ahead to where it mentions the concept of thermodynamics, and you would be set. I see it saving you a lot of money and time investment that could be put towards things that would give you more satisfying results, and I would love to see your determined mind and strong effort working to advance the EV revolution.

Best Wishes,
-Luke

 

[myzter]

okay, well - im not well learned in physics. good for me
I didnt know a dam thing about any engineering one and half years ago
but right now .. Im trying to balance the relationship between a motor and a dynamo
mechanically, electrically & magnetically i guess...........

 

[Arlo1]

Myzter- I would love to see your determined mind and strong effort working to advance the EV revolution.

Best Wishes,
-Luke

Exactly what I am getting at and where I have directed my efforts in my future as well. Good luck.

 

[Arlo1]

PS: I see you're from Nanaimo. Despite being a Brit I've spent a lot of time there, working out at CFMETR back in the mid-90's. I'm reminded of it right now, because we're having some pretty damned cold weather here in the UK, cold enough for me to get out a rabbit fur hat I bought in Nanaimo fifteen years ago.

Haha yup I live in paradise! I moved from edmonton which had nothing for me (other then some ice tracks in the winter which for new years was alot of fun with the poor srt4 lol) now I put up with some rain instead of -10-30 all winter and my summers are 6-8 months long. Its great for ebike rides and motorcycle riding ect.

 

[liveforphysics]

okay, well - im not well learned in physics. good for me
I didnt know a dam thing about any engineering one and half years ago
but right now .. Im trying to balance the relationship between a motor and a dynamo
mechanically, electrically & magnetically i guess...........

To best visualize the relationship, imagine they are on the same shaft. Imagine your left arm has a little crank and is turning the shaft, and your right arm is hanging onto the crank being moved. You can increase resistance with the right arm, and you have to increase the work you put in with the left arm to compensate. This is the balance between coupled motor and generator.

 

[myzter]

If anyone is interested in constant regen.. harvesting energy from wheel weight in motion
Swapped out previous test gears
25:1 to 1:1 generator to rear wheel rotation

measurement of power draw made with Turnigy watt meter
/ motor rotation reversed only the freewheel/sprocket turning
compared to fwd motor rotation turning generator, charging battery
(rheostat as load / wired to negative lead before battery)
AC/DC power source for a constant amps/voltage tests

Baseline
Motor turning ONLY the freewheel/sprocket in reverse
1.73A / 13.3V / 23.1 watt
-
motor fwd spinning wheel, gears, and generator
1.65A / 13.4V / 22.1 watt
cells charging @ 5.93V / 0.24A / 1.42 watts
2x LiFePO4 cells series / resting voltage 5.85 volts

Testing @ higher voltage for Increased wheel speed resulted in :

Baseline
Motor turning ONLY the freewheel/sprocket in reverse
2A / 19.3V / 38.6 watt
&
motor fwd spinning wheel, gears, and generator
1.92A / 19.8V / 38 watt
cells charging @ 6.08V / 0.31A / 1.88 watt
2x LiFePO4 cells series / resting voltage 5.85 volts

Could be just the motion of ONLY the complete rear wheel up-off the ground is able to generate nearly 1.42 - 3.77 watts

Scaled the test up ..

motor fwd spinning wheel, gears, and generator
1.93A / 19.7V / 38.6 watt
cells charging @ 9.56V / 0.32A / 3.05 watt
3x LiFePO4 cells series / resting voltage 9.37V

motor fwd spinning wheel, gears, and generator
1.89A / 19.95V / 37.5 watt
cells charging @ 13.02V / 0.29A / 3.77 watt
4x LiFePO4 cells series / resting voltage 12.66V

Any questions
Myzter

 

[myzter]

New video /results may vary..
[youtube]CNJmu0JTBFI[/youtube]

any

 

[Momentous]

Myzter.. i have never seen this done before !

Can you account for the friction in the freewheel bearings as the possible extra drain ?

cheers

 

[liveforphysics]

Brush timing.

Brushed motors for applications have an advance or retard depending on what they are trying to suit them towards.

This means the no-load in the advanced direction might be 30w while the no-load in the retarded direction might by 5w.

 

[myzter]

yes I have seen a video about what liveforphysics mentions..
I guess I might perform an equal motor load test in both directions..

However... this is a Currie motor and what i've seen is that they are usually mounted faced inwards

On this ebike the polarity is connected backwards, to advance the bike forward
negative battery lead connects to positive motor connection

thanks

 

[liveforphysics]

If your forward direction is operating at reverse polarity, that would of course explain it. The curie motor has a timing advance.

 

[myzter]

Oh well, fun for a couple hours..
I will run the motor in both directions ..in few hours time.. off the bike

This will not effect my solar fairing design.. summer cannot arrive soon enough !!

thanks

 

[oatnet]

You could save a ton of money, weight, time and expense and just remove the wind setup and parasitic generators and just replace them with a big 200-300w resistor you put across the battery terminals. It would run silently taking up minimal space while accomplishing the same end result.

:lol:

Well put! The over-unity cycle is like world peace - often touted by airheads but not possible in nature.

-JD

 

[myzter]

Too bad, really what was I thinking regeneration on flat ground !
I dont have millions of dollars to sink into R&D, like a large Sanyo can

what the $%^#! ever - TROLLS!
thinks using a generator it has got to be slowing the vehicle down..

Im wasting my time/money on project: THEKPV

SANYO Releases New “eneloop bike” Electric Hybrid Bicycle

.. By traveling 1 km in “Eco Charge Mode” over flat ground, enough electricity is generated and stored to travel about 300 m in “Power Mode.

http://sanyo.com/news/2010/03/02-1.html

 

[oatnet]

thinks using a generator it has got to be slowing the vehicle down..

Im wasting my time/money on project: THEKPV

Nobody is worried about a generator will slowing you down; everyone has pointed out that you have to put far more energy into the generator than you are can take out. Your inability to grasp this concept tells me you are way beyond your capabilities in a hobby that can be dangerous. Flat ground makes this design even more useless - Nobody is gonna pedal TWICE as hard for 10 miles to generate enough current to ride 1 mile.

I'd say go ahead and waste your time/money on THEKRP if it makes you happy. However, if you post your imaginary progress here, where folks are not challenged by understanding basic laws of nature, you can expect everyone to point and laugh. Don't worry about those people you call Trolls, they are merely sane.

When you get tired of trying to achieve overunity, might I suggest looking into similar fields, like the water car, Antigravity, FTL travel, time travel, or teleportation?

 

[myzter]

...The O word is not found in my descriptions, I illustrated the clips with details for future references ...
The real focus is about harvesting power for on board electronics / charging a booster pack / supplementing the main battery pack or engineering together all three.. so, the brightest ES naysayers must have this all figured out and the topic has no usable applications even though worldwide.. products and devices are released continually.

GooD DaY!
T

 

[Arlo1]

Myzter.
Why don't you do some tests to prove to us how well your bike works. Here is the best way. Find a stretch of road you can drive to drain you batteries and see how far from home you get before the batterys are dead. Then unhook all your regen motors and just use the drive motor and travel the same path and show us how far from home you can get.
Just make the test acurate by using a fully charged battery both times and travel excatly the same path both times!

 

[oatnet]

The real focus is about harvesting power for on board electronics / charging a booster pack / supplementing the main battery pack or engineering together all three.. so, the brightest ES naysayers must have this all figured out and the topic has no usable applications even though worldwide.. products and devices are released continually.

GooD DaY!
T

You should be the Poster Child for "Ineffective Ingenuity"

Your "solution" converts electricity to mechanical energy, then converts the mechanical energy back to electricity, at about 20% effeciency. It costs hundreds, adds significant weight, and introduces dozens of mechanical potential points of failure.

A $5 DC-DC converter is only one point of failure, will meet all three "design criteria" with 90% effeciency, and only add ounces. It is cheaper, lighter, more effecient, and more reliable.

Which option do you think qualifies you for the tin-foil-hat brigade?

Oh, and charging a booster battery from your main pack is ALWAYS stupid. Why take 100wh from your main pack, put 90wh into a booster pack (Lose 10%, assuming the more effecient DC-DC converter), so you can take 58wh from the booster pack (lose 35% during charging). Why add all of this hardware/weight/complexity/expense, when simply using a bigger pack is cheaper/lighter/ simpler/more reliable? Because the voices coming from your Alcoa Sombrero are telling you to.

And in what way does this supplement the main pack? All it can do is put back less energy than it took?

-JD

PS - please point me at ANY of these "products and devices are released continually" to address your stated 3 "needs"? I don't believe you.