Questions about building an e-bike

Diosky

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May 8, 2008
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Ok not sure if these questions have been answered somewhere else and if so please don't flame me and provide the thread links and I will happily do the reading.

1. Is it possible to use ultracapacitors to power an e-bike? There doesn't really seem to be a definitive answer to this

2. would it be possible to use a solar array on a bike to help generate energy to sustain longer trips if so...or could you use solar power to charge the a123 lithiums?

3. using the above methods if possible, what would be the best setup for range/power? I plan to use the bike for traveling through both europe and asia if that helps.

I am not experianced in any of this technology or eletrical engenering at all but am considered by most a very intelligent (though albiet poor spelling) individual and learn fast so any and all help will be greatly appreciated. I am planning on using a tadpole style recumbent tricycle that I am building with a friend and would really like it to be assited mainly for hill climbing but if its possible to get enough range I will also use the electricle assist for flat roads/paths as well. Thank you in advance for any help or pointing me in the right directions. Also try to use laymans terms because as I said I do not really know much about how all of this works though I have been doing alot of research myself for awhile, its just I understand more when I actually work on something in regards to science/mathmatics than just reading formulas with no real thing to reference. Oh and forgive my poor spelling as I know it can be atrocious.
 
oh crap just realized there was an EV bike section on this forum......can someone ask a moderator/admin to move this into that section?
 
Ultracaps. Probably, wait till eestor hits the market.
Solar. well there is this... http://www.gizmag.com/go/4430/4/

Best design for a long distance trip?
good gears so you can pedal. hub motor great batteries. small diesel generator to charge the batteries, and a solar array built into the bike for solar charging. You stop to eat/sleep then plug in.


Long trip and know nothing about electricity and electonics - -bad plan - - have a friend who is go along or take some lessons from someone who is who can show you specifics about your setup.
 
Take a voltage convertor and a charger.

Solar panels will be next to useless... you can charge your peripheral electronic equipment with a tiny dynamo.

:mrgreen:
 
Ok maybe I worded that poorly but I was trying to make it quick because I had to run. Its not that I know nothing about electricity or electronics, I just i feel much ore at ease with a group of people like yourselves who seem to have done alot of this stuff in real world situations and not just on paper (not everything on paper works out as well as it should). Though I will not claim to understand everything to great complexity, I do have a tentative grasp of the situation and the things I am asking about, but it seems that everywhere I look and find research, its constantly at odds with the next bit of research I run across. One paper will say ultra capacitors are a waste of money for EV vehicles and do not allow for long enough bursts or enough energy storage. Another says they worked great and the only issue was price. Same seems to be the problem with solar power.
So far I wan't to use the a123 cell (which I know I can get on ebay from the dewalt packs) as they seem the best option for damn near every reason. A friend of mine who lives completely off the grid was the one who told me about ultra capacitors and to check them out as a viable energy source for my bike because their cycle like is supposed to be about 1 million cycles (at minimum 500,000 from what I have read) which means unless the caps were 1,000x the price of lithium batts that it would be the better investment in the long run. Now from what I have gathered they do not seem to be 1,000 times the price but maybe i am not understanding something soimewhere along the lines. Also I would later like to use my bike as the frame to build a true EV-HV (Like a velomoble) and I know that will take even more power and more storage. That and if I am not mistaken the ability ultra caps have to store energy almost instantly and work great in combination with regen braking, it seems like a win-win situation.
Also I did not want the solar panels for charging peripherals, I wanted it for an additional power source to help lengthen the cell life if it seems possible (and from what I have read it seems to be mixed responses). As for eestor, don't know if its true or hype, and I will be happy if it is true, but as of now I want to build this in the next 4 months so if its not out by then, than its not going to happen (or if its out of my price range). I had read that article Lesssss and I was thinking something either along those lines or one that was always open on the rear of the bike. Thanks for the idea about the diesel, though I would prefer if possible to stay away from using gas, though I wonder if it would be possible to convert a small diesel to run on veg oil like you can with car sized diesels?
 
Diosky said:
1. Is it possible to use ultracapacitors to power an e-bike?

Theoreticly, Yes. But the usable energy density is stiill lower than SLA batteries, So they are still a long way off from being practicle.

Diosky said:
2. would it be possible to use a solar array on a bike to help generate energy to sustain longer trips if so...or could you use solar power to charge the a123 lithiums?
Yes, and Yes. But unless you are building something the size of the solar racers they run out in the desert, you aren't going to be able to carry enough pannels to make much diffrence. wind resistance becomes a serious factor, too. an Aray big enough to catch enough power to contribute anything would probably make a pretty good sail. Unless you have a tail wind, that would be a bad thing.

A more practicle aproach for Solar and Ebikes is to leave the solar pannels at home charging a large battery all day, then use the power to charge your bike at night, 100% off the grid. That doubles as an emergancy power source for your house if you need it, with a 110 inverter.


Diosky said:
3. using the above methods if possible, what would be the best setup for range/power? I plan to use the bike for traveling through both europe and asia if that helps.

The best setup is going to be skipping all the fringe technologies, and staying with whats proven to work long term, Such as the A123 cells and a well build, efficent bike.
 
Drunkskunk said:
best setup is going to be skipping all the fringe technologies, and staying with whats proven to work long term, Such as the A123 cells and a well build, efficent bike.

Thanks for the information, definitely helpful and I can understand wgat you mean by a sail in regards to the panels. So another question then....are the a123 cells the best to use or is there a better lithium on the market (not one where you can only get if you are ordering huge numbers but something availble to the public)?
 
A portable solar array would only provide enough power to charge your peripherals on a daily basis. Dynamo better for that.

To run straight VO (veggie oil), you need to heat it to ~200F before passing it through the injection pump. You also need to switch back to diesel or bio-D before shutting down.

Not practical for a bike, unless you use a trailer with a diesel motor to push you long distances while charging your batteries, then use just the e-bike for local trips.

:D
 
There is no better lithium battery than the A123, but there are cheaper ones. The A123s are only realistically available in the 36V DeWalt battery packs, which you have to open up and extract the cells from. (But you get a 10s BMS out of it too.) Those packs retail for $160 which is $16/cell, but they can usually be found on ebay for $100-120. That gets you 33V and 2.3 Ah.
 
Diosky said:
So another question then....are the a123 cells the best to use or is there a better lithium on the market (not one where you can only get if you are ordering huge numbers but something availble to the public)?


Best is relitive, But yeah. Best on the market that the average consumer can get there hands on. dewalt packs on Ebay are the ticket, although A123 will sell you individyal cells, at 6 cells for like $110. Emoli and Lifebatt cells are close, but not as good. For the specs you listed: Long life, and durability, there isn't anything better on the market.


Another note on Bio Diesel. It sure burns clean, but it has a lower energy density then Conventional Diesel, so you would need to carry around 30% more fuel for the same output on the generator
 
so you would need to carry around 30% more fuel

No you wouldn't. 9%:

http://en.wikipedia.org/wiki/Biodiesel said:
The volumetric energy density of biodiesel is about 33 MJ/L. This is 9 % lower than regular Number 2 petrodiesel.

To run straight VO (veggie oil), you need to heat it to ~200F before passing it through the injection pump.

I think that might be true for all readily-availabe small engines but it is not true for some popular Mercedes cars.

http://en.wikipedia.org/wiki/Vegetable_oil_used_as_fuel said:
Many cars powered by indirect injection engines supplied by in-line injection pumps, or mechanical Bosch injection pumps are capable of running on pure SVO/PPO in all but winter temperatures.

A person I know runs her Mercedes on plain old (filtered) restaurant waste oil for more than half the year.

... the fact remains that in today's world biofuel from non-waste-oil sources is not really eco-friendly at all. In terms of CO2 emissions, anyway.
 
Well thank you to everyone for all your helpful replies, I really appreciate it :)
 
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