Mini gas hybrid ebike charger with off the shelf components

[Grizzl-E]

Hey I'm not sure if anyone has done this yet. But I have been kicking around ideas for a mini generator to recharge the batteries on my next build.

It occurred to me today that I already have the components I need. At least to make a proof of concept.

- 44cc weed whipper engine as an ice power source.
- 6374 rc motor as a generator
- direct drive / belt drive / helical drive to match optimum ice rpm to my desired voltage based on motor kv (haven't done the math on this yet)
- 6fet controller that I can flash to enable regen

Seems like it should be as simple as:
1. Hook up the controller leads to my bikes battery
2. give the ice a throttle bump from the Rc motor to start it
3. Once the motor warms up hit the regen lead and open up the throttle on the ice (or reverse that I'm not sure)
4. Enjoy the awful sound of a weed wacker ice spinning a noisy rc motor
5. Turn off motor once desired voltage is reached

Anyone see any issues with that?

I take my bike pretty far from civilization up here in Canada and I have been kicking around ideas to recharge my batteries at a decent c rate. (Solar is too expensive and unreliable at these latitudes)

 

[Grizzl-E]

Oh I should mention that I use the bike for pulling my trailer with inflatable boat across portages so I already carry gas.

And exploring of course.

 

[dogman dan]

There is a thread from another guy who made some flyweight generators, somewhere on this site. Sorry, don't have it located though.

His was to be mounted on the bike at all times, so maybe try hybrid in the search.

 

[Sunder]

Dogman is referring to this post:

https://endless-sphere.com/forums/viewtopic.php?f=3&t=68164

My first post, so please forgive any faux-pas ( and correct me to what I should have done ) but I thought I'd introduce my project - It's an Electric-X ( Extended Range ) bicycle project. It combines an battery-electric system with a small generator that has the throttle controlled based on the load being presented to it, so it can charge the battery during use of the bicycle, so it's not technically a hybrid, which allows both petrol and electric motors - it's an Electric-Extended system.

My thoughts is that anything big enough to be reliable is going to be too heavy for a bike, and anything too light is either not going to generate enough power, or not last very long.

I don't mean to be a downer - carrying it in your trailer would be fine, but I don't have a trailer, and like my bikes to be agile and responsive so it wouldn't suit me.

I had looked into the possibility of a Butane fuel cell - it'd take 24 hours or even longer to recharge the battery to full, but it'd then be a never charge bike - just change the Butane cannister once every few weeks. Conclusion - also not feasible, but in either case, I'd love to be proven wrong. If someone can make a reliable 100W micro-generator for under 4kg, I'd love to see it or even buy one off them.

 

[ebent]

Maybe the answer is to have a big ass battery along with a generator or 2 in a strategic location on the property?

 

[Grizzl-E]

Thanks guys for the input! And thanks Dan for the link.

I thought about building a hybrid type drive like that but I don't even like running my motors without a foc or at least sine wave controllers. I have a kawi zzr1200 for when I want the noisy gas lol.

I already have ~ 5kw of batteries from my various builds that I could charge and take with me. But like Dan I like my bikes light and agile. I don't like to carry more than 1kw on the bike. Especially since my backwoods bike is a mxus 3000w fat tire build right now.

I was thinking of picking up some new 3500mah 18650 cells but I won't gain much weight savings over what I have now.

I live in Manitoba so the distances can be crazy. I can drive 10 hours north (in my truck) and not be across half the province. I have my meanwells to bulk charge off my trucks inverter really fast but once I leave the truck there is typically no power access at all.

 

[d8veh]

You already have a generator (hub-motor) and a charge control system (regen). You only need to turn the wheel. Would it be easier to use a small as motor with a friction drive to the wheel? You could also use it to drive the bike if necessary. Have a look on Youtube for "bicycle friction drive". There's loads of them.

You can get some very powerful 4-stroke R/C aero engines that only weigh about 1kg. I'm sure one of those could be adapted.

 

[MadRhino]

building a charger with fuel cells would be smaller and lighter, with better efficiency than an ICE generator... yet this could be an expansive project right now. That is the future: Charging your bike with a small H cartrige. :wink:

 

[ecycler]

I think you should go ahead and try it. I guess there are some significant safety factors setting it up direct drive to your wheel and activating regen on your bike's controller, huh?

If you really want to package it with a smaller/lighter/durable 2 smoke, then check out the zenoah g2d 22cc engines (and available upgrades) used on scooters and large RC models. I was able to eek out more than 2hp from one back in the day, but if I remember correctly there were some pyschos getting 3+hp.

Would be lovely to listen to that reed engine hum at 9k rpms at full throttle and blow all kinds of blue smoke into the woods for a few hours at a time. LOL