eBike / Generator / Power Source

[nerve]

Building my first ebike! great info on here...

This is what i have:

Cromotor
18FET 4110 lyen controller
36V 15aH 77w continous BMS LiFePo4 Battery (I only have one battery at the moment...)

I am wondering if I could also use this equipment not only for an ebike, but also as a small offgrid power source? Inverter? Solar Pannel? Can a Cromotor be fashioned into a wind generator to charge the battery too ? Can the Lyen controller be used as an inverter to safely power something other than a hub motor?

what do you guys think about this setup in general?

 

[e-biker]

A cromotor and 18fet lyen @ 36 volts seems like waste of a really good setup. what is top speed @ 36volts?

 

[nerve]

25mph. I think...have not fashioned it all together yet...But I wanted a street legal ebike commuter with the option to add more power down the road. 325lbs is the total weight load...

 

[spinningmagnets]

The brushless hubs that are common around here will put out some voltage when they are spun. Regen is proof of that. However, these hubs were not designed to perform their best as a generator. This ine of thinking has been pondered before. The wind changess direction, and also there is much more wind about 60-feet above ground level, as long as there are not any trees nearby. Wind-generator towers are cumbersome and somewhat expensive in relation to the amount of power you can get by having some sort of turbine spinning a roller that drives the tire to recharge your batteries while you are at work.

I would guess that your best bang for your buck to recharge your bike off the grid would be to have a decent-sized solar-panel charging a deep-cycle battery bank, and use the battery bank to charge your bike.

If you are asking if you can use your E-bike battery pack as a back-up power source, the answer is yes. If you want to use off-the-shelf inverters to make 120VAC, I believe a 48V pack would be the easiest to set up. There are 24V off-grid inverters (for sailboats), but I haven't heard of 36V or 72V components for this.

I have chosen a 12V interface for my back-up power. I have a 45W solar-panel that is in 3 sections so it can be folded to fit through a door, allowing it to be stored indoors in the evening. with 12V I can charge AA batteries (Sanyo eneloops) for pocket flashlights and a couple lanterns. The panel charges a large 12V deep-cycle battery, that I can also use to charge my cell-phone and laptop.

I would love a more comprehensive system if I could afford it, but this is what I have right now. I think it would be very inefficient to run a TV with a 48V E-bike pack driving a 120VAC inverter. I would be more likely to use 12V to watch Hulu/Netflix and the news on the web through my laptop.

http://otherpower.com/, and their chat forum, http://www.fieldlines.com/index has a lot of off-grid info. Also http://www.thebackshed.com, and http://www.builditsolar.com

An ebike controller is not set-up for the type of duty you describe. spinning the rear tire will create regen, and I honestly don't know if it would work well or fry a part that was not designed for continuous regen heat over hours of charging. It might be an interesting experiment.

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Cromotor, it is heavy/wide so that it can take a LOT of amps. A lot of people are happy using 25A on a 9C and a 6-FET controller, and 35A on a Crystalyte HT and a 12-FET. The Cromotor on an 18-FET can run relatively cool at...I'm guessing 45A? with occasional temporary bursts of 60A (I've never owned or ridden one). You will need LiPo for the C-rate, and even then a 72V / 45A continuous-capable battery pack will be large and expensive.

Best of luck with whatever you decide.

 

[nerve]

Thanks for the info spinningwheels. Im trying to understand if there is a way to charge the battery offgrid, aside from a solar pannel. Im open to ideas, even if it means physically pedaling the bike backwards on a mill for three days...lol

 

[lbz5mc12]

haha he called you "spinningwheels".

 

[nerve]

:lol:

 

[dogman dan]

You can pedal power back into your bike, but efficiency is pretty bad. Bear in mind that at 25 mph, you can ride 25 miles on 10 -15 cents of electricity. But it might take about 10 bucks worth of food to pedal it back in.

Pedaling power into the bike can have it's uses, such as when the grid is down. But as a do it regularly thing it's not great. Best bet is a solar or small wind charging station. About 100-200w of panel and a storage battery to run your charger.

Nothing really that wrong with oversizing the motor, except the weight and the cost. But you won't likely fry several motors like I have.

 

[nameyourself]

Most cheap brush motors make decent pedal generators if you gear 'em. I had a 250w MY1016 based pedgen for a while and it wasn't terrible.

edit; wrong pic..don't do that.

 

[nerve]

dogman, "You can pedal power back into your bike, but efficiency is pretty bad."

-Do you know how this is done with my setup? Is this related to regen or just simply pedaling without throtle charges the battery? I have the regen jumper connected and an e brake on the Lyen. If I my understanding is correct, is regen basicly a rectifier that creates a 6-pluse DC output from the spinning cromotor?

nameyourself, how did you gear it? I'm imagining lots of leverage?

 

[parajared]

After fiddling with mid drive hub motors a bit I have found that it isn't very hard to put bicycle chain cogs on motor shafts. Though I haven't personally tried it but I could see anchoring a car alternator to the wall or something and peddling away frantically for some sweet sweet energy.

Alternately using Lyen's USB cable you can program regen really high on your controller then peddle with the rear tire in the air. Connect the battery you want charged to where the battery normally hooks up. This would charge your battery for you. No telling how effective this would be though.

 

[nameyourself]

nameyourself, how did you gear it? I'm imagining lots of leverage?

Using #25 sprockets and chain I made a simple 2-stage step up...

The MY1016 motor I had came with a #25 11t sprocket. If the jackshaft had a 55t and an 11t, and your pedals spin a 55t linked to the 11t on the jackshaft, you should get a 25:1 increase..meaning 100rpm at the pedals would be 2500rpm at the motor.

 

[nerve]

i'm thinking about going camping with a solar panel attached to a bike trailer. How do I wire up a solar panel to get charge while biking? Would I need the battery charger and an inverter?

 

[dogman dan]

It would depend on the voltage and amperage of the panel, and the voltage of the battery charged, the kind of battery you have, etc.

Dumb example, obviously a single 12v panel won't push power into a 36v battery. So at a minimum, the power would need to be converted from 12v to 36v charger voltage.

So how about 3 12v panels connected in series? That's 36v right? It should be, at noon. But if each panel puts out say, 12.2v, then three in series puts out 36.6v. There is still a problem, since most 36v batteries charge to at least 42v, or more.

Step one would be finding out what your panels actually produce. At most, a 45 watt panel will produce 270 watthours of power per day. Less in most places with less sun than the desert southwest. A 36v 20 ah battery has nearly 800 watthours in it. So there is the first problem, a small harbor freight solar kit is a bit on the small side unless you have several days to let the battery charge. If your battery can break into sections, and be charged at 12v, then the typical 12v charge controllers should work to charge the battery at 12v.

To run an inverter, to run your charger, you'd need another battery. Panel, charge controller, battery, inverter, charger, bike battery. With some losses at each step. Even with those losses, it can still be the most practical way to set up a stationary charging power supply at home.

 

[nerve]

Thanks for the info dogman. It amazes me how little I understand about energy in general, im hoping to learn alot with this project. I'm thinking a small generator would be the best option. If I bring along my charger 43.8v 4A for a 36v 15aH lifepo4 how do I calculate what size generator I would need and how long it would take?