Solar electric ebike - no battery required

S

SolarCross

New Member
Those of you interested to know, it is possible to ride a 2 wheeled e-bike on solar power alone without any battery needed...
p4pb10154241.jpg


And this is the video to prove it...
http://www.youtube.com/watch?v=go9vbhrXoEU


project: SolarCross
http://www.solar-cross.thekpv.com
 
Can that really put out, say, 250 Watts? (And that would be a weak e-bike)

Not to mention the fact that it'll only do that much when the Sun is shining.

Not that I really want to rain on your parade. But one should be careful about promising too much.
 
I think it was awesome. great job, he didn't promise anything, he said level ground when sun is shinning, great motorized bicycle solar cross and welcome to the forum
 
Thanks Paul

Well.. I can of course still pedal along and really utilize the <100watts output from the solar panels... kinda like a solar assisted e-bike... I also have switches and relays and supercapacitors to test all sorts of configurations.... this was purely a solar panel to motor connection... that demonstrates the power transfer with nothing in between.. The motor is probably under <80% efficient ... so I think its a good proof of concept...

I tried this solar setup with a 1000watt (7T sprocket) and 350watt (11T sprocket) brushed motors... with identical results in the top speed...

The smaller 7T motor sprocket makes a huge difference in torque at low speeds and during climbing steep grades... however to do it requires a custom coupling on the motor shaft... and they last just over 1000km's before needing to be replaced... A single reduction would be a better solution for longevity...

here is another video...
http://www.youtube.com/watch?v=mAZ6xWOcP9M

brnot
 
that snow makes me shiver lol. great video, what motor and battery are you using on that set up, my next bike i am thinking about trying something instead of a hub motor. Motorized bicycles most definitely provide many smiles per hour
 
If they can drive solar powered cars across the Australia, we should be able to come up with a practical solar-electric assisted bicycle for sunny climates.
What if we took something like this reverse trike and installed a small hub motor and attached solar panels all over the body of this rig?
speeder_front600.jpg
 
Whoops! I think I made an error. I assumed that the OP was merely pointing us to a neat bike that he'd spotted on youtube. I should have looked more closely.

Now I still am skeptical of getting very much power out of the Sun, short of some major improvement in technology. But that's very unimportant in this context.

The actual inventor of this machine deserves congratulations and admiration. And getting 100 Watts out of a ride-able bicycle is an accomplishment, after all.

So, Solar Cross, my hat is off to you.
 
paul said:
that snow makes me shiver lol. great video, what motor and battery are you using on that set up, my next bike i am thinking about trying something instead of a hub motor. Motorized bicycles most definitely provide many smiles per hour
Click to expand...

The motor was just 1000watt 36v, the controller was also 1000w 36v but after monitoring the power with an watt meter.. I was seeing peaks of 1200-1300watts.. the torque from a 7T sprocket is comparable to other ebikes that draw several 1000's of watts.. +50km/h speeds..would require more voltage... but its possible...

I actually tried a 5T sprocket couple years back, and it had so much torque the motor shaft twisted into two pieces...
motor-panel.jpg

thats with just a 750watt motor on 36V.. (10mm shaft)

the small tooth count sprocket (7T) on the motor is really what enables the fun performance... but it comes with a price... as much faster wear is noticed.. and increased maintenance (chain retention) needed.. The stock 11T motor sprockets will last a heck of alot longer but you dont get the standing low speed torque...
ie. every tooth lost is 10% more torque gained - 10% lower top speed.. approx...

The solution is probably as simple as a 1 stage reduction...
11t motor to a 22T+ sprocket on a shared shaft with an 11T sprocket on the end, driving the cranks on a 95T sprocket.. (#25 - 1/4" chain)

The batteries were cheap Lipo from hobbyking..
approx. 40V @ 8000mah - 10 cells / 1850g ($180 + ship)

Ive been watching the newer chemistries from Panasonic.. same type batteries that go into the Tesla cars...
approx. 40V @ 8250mah - 15 cells / 1350g ($135 + ship)
but the pack needs to be built - soldered together etc...

Just awesome man.. Too good.. I will try to have similar solar panel set up.. Very very nice stuff.
Click to expand...

Thankyou LeslieBanks

I made the panels from Plaskolite..
HomeDepot
 
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oh
With 40V @ 24Ah I have road from Squamish, BC to Vancouver, BC - 68km
my front porch to top of Lions Gate bridge in 1hour : 58min
I did pedal the entire time - fast .. a steady sprint, on flats I was keeping about a 10A draw and on hills 20A draw..
 
SolarCross - What kind of motor controller did you use with the solar panels? Seems the output of the solar panels would be less than the low voltage cutoff of my current controller.
 
I like the idea of solar panels to charge your battery - live off the grid without gasloine. The panels on a bike are just too awkward and don't have enough output for robust power.
 
In the video the solar output (8volt @5Amps) from the front array is wired in parallel with the output from the rear pv array (8volt @5Amps) directly to the motor (8V @10Amps). no controller.. /amperage is also known as range

If your keen on the latest research & PV tech, you'd know where this could go...

Here is a pic of 1 panel - 95 gram
img_4_1385326759_7e06da3ad5983cfd396b127bfdf410d0.jpg


I carried all 8 panels onboard a 2 week >600km solo bike trek this summer..thru the Okanagan valley/Kootenays.. (friends would hitch to the next town/beach camp -where I'd meetup) only utilized the panels once the whole trip, to recharge my 12V booster pack way ontop a mtn. where there was no AC.. It was a rough adventure (mainly because my charger's PSU was $***!)... but almost worth every second..
p3pb10050441.jpg

(not shown is the 50lbs sack I shouldered)
 
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