Electric X development - Petro-Electric bicycle project.

[NOVISCOTT]

In fact, the pedelecs you see people riding around on? I doubt any would be over 400WH, so even if you did a slow overnight mains charge, you'd have three times the range they have, and some people quote up to 50km for one of those.

My Pedelec is 500WH (Trek Powerfly 5) and is good for in excess of 50km on "sport" mode for my commute/weight (mix of path, road, fire trail and single track with approx. 400m elevation gain, and an 80kg rider). I've pressed it out close to 60km but have sometimes knocked it back to "tour" when getting nervous about making it home. Though have never run out.

I haven't tried longer riding on "eco" to see what sort of range it gets as the Trek is more about fast fun than racking up kilometres. I have a roadie for that.

That's about 12.5kg for batteries, 6kg for generator and fuel, and the rest for the electric drive and wiring.

As a Mechanical Engineer (with a fair bit of automotive experience) I find the project quite interesting. I do wonder when you are getting up to these weights whether stripping down something like a Yamaha EF1000iS to it's bare essentials and customising a housing/fuel tank would be a good starting point.

[zebee]

But... Charging at night means riding in silence, and at night you can have extra light from the generator in case you carry a tent, as well as charging anything that needs charging. 600W is a decent power budget for camping. Maybe not enough to boil water or heat your food. If you wanted to use smaller batteries, that would be possible too, but the 1C rate for maximum generator output is around 50A at 12v, 25A at 24v and 12A at 48V.... So if you were running a normal system at 48v, then you would want at least a 12AH battery system.

Though... If you want to try assisted cycling, I'd say try it with a normal battery/wheel combo first... You'll get a feeling for what you want pretty quickly after trying it, even for just 10-15km. If that works well for you, plan the upgrade.

Regards
David

Charging at night seems reasonable. I use solar power for light and gas for cooking, but looks like I'd need the battery for light while riding as I'm not sure a 20" wheel could fit a motor and a spoke dynamo. Could look at putting the dynamo on one of the front wheels maybe. Or just fit the spoke magnets to the electric motor. But then I doubt I'd need a lot of hours of lighting and modern LEDs don't need much juice.

I have tried an electric bike, as I bought a Gomier trike for my mother and rode it 20km home. Was very impressed with the feel, although 30kmh on an upright trike is a bit energetic really.... Weight is a bit of an issue, as I don't want to use the juice all the time but given your weight info there it might be necessary as even a Greenspeed GT20 isn't as light as a lot of upright bikes are, and it's not a heavy trike.

I have been thinking about electrifying the trike because it is the heavy hauler (with trailer) and while I can do the 20km to work unassisted (up a very nasty hill) having a bit of help might mean I do it more often. RIght now I cheat and take a train for that bit. A motor means the haulage and the commute would be simple.

Zebee

[cj7hawk]

In fact, the pedelecs you see people riding around on? I doubt any would be over 400WH, so even if you did a slow overnight mains charge, you'd have three times the range they have, and some people quote up to 50km for one of those.

My Pedelec is 500WH (Trek Powerfly 5) and is good for in excess of 50km on "sport" mode for my commute/weight (mix of path, road, fire trail and single track with approx. 400m elevation gain, and an 80kg rider). I've pressed it out close to 60km but have sometimes knocked it back to "tour" when getting nervous about making it home. Though have never run out.

I haven't tried longer riding on "eco" to see what sort of range it gets as the Trek is more about fast fun than racking up kilometres. I have a roadie for that.

That's about 12.5kg for batteries, 6kg for generator and fuel, and the rest for the electric drive and wiring.

As a Mechanical Engineer (with a fair bit of automotive experience) I find the project quite interesting. I do wonder when you are getting up to these weights whether stripping down something like a Yamaha EF1000iS to it's bare essentials and customising a housing/fuel tank would be a good starting point.

That's a very heavy generator... It's manual start/stop and 12.5kg. You might knock off another kg by lightening it, but that's without fuel.

I can put out the same amount of power in 6kg from scratch and at 24v. Around 10 times the DC power of the Yamaha, so it's not really in the same category... Actually, I don't know of many generators in any size that can put out 1kW of low-voltage DC, which is legally required for a bicycle.

Anyway, as a mechanical engineer, you may find it interesting that nearly all of my generator is 3D printed in ABS, including all of the structural parts ( except nuts/bolts ) - And the generator core and electronics. And of course the 4-stroke motor.

A lot of the weight still comes from batteries. I can reduce battery size to cut back on weight, but there's also the main electric motor to consider, so sometimes, it's better to just assume a weight hit and go for the capacity you want rather than trying to cut too many corners.



David

[cj7hawk]

But... Charging at night means riding in silence, and at night you can have extra light from the generator in case you carry a tent, as well as charging anything that needs charging. 600W is a decent power budget for camping. Maybe not enough to boil water or heat your food. If you wanted to use smaller batteries, that would be possible too, but the 1C rate for maximum generator output is around 50A at 12v, 25A at 24v and 12A at 48V.... So if you were running a normal system at 48v, then you would want at least a 12AH battery system.

Though... If you want to try assisted cycling, I'd say try it with a normal battery/wheel combo first... You'll get a feeling for what you want pretty quickly after trying it, even for just 10-15km. If that works well for you, plan the upgrade.

Regards
David

Charging at night seems reasonable. I use solar power for light and gas for cooking, but looks like I'd need the battery for light while riding as I'm not sure a 20" wheel could fit a motor and a spoke dynamo. Could look at putting the dynamo on one of the front wheels maybe. Or just fit the spoke magnets to the electric motor. But then I doubt I'd need a lot of hours of lighting and modern LEDs don't need much juice.

I have tried an electric bike, as I bought a Gomier trike for my mother and rode it 20km home. Was very impressed with the feel, although 30kmh on an upright trike is a bit energetic really.... Weight is a bit of an issue, as I don't want to use the juice all the time but given your weight info there it might be necessary as even a Greenspeed GT20 isn't as light as a lot of upright bikes are, and it's not a heavy trike.

I have been thinking about electrifying the trike because it is the heavy hauler (with trailer) and while I can do the 20km to work unassisted (up a very nasty hill) having a bit of help might mean I do it more often. RIght now I cheat and take a train for that bit. A motor means the haulage and the commute would be simple.

Zebee

If the motor is direct drive hub, then why have a dynamo at all? Just rectify the circuit, and include a parasitic buck/boost converter to drive the lights and charge a small battery... That would replace the dynamo entirely. Or you could just rectify the signal, buck/boost convert and drive the light without a battery at all. Your mechanical losses would go down too.

I'm not a strong rider, but when boost is on, I can tackle steep hills like a pro... Without breaking a sweat... OK, I lied about the sweat - I'd sweat even if I wasn't pedaling, but you get the idea.

The dynamo isn't needed then, and you can get a constant voltage out of your system that way, regardless of speed - though I really would recommend a very small lithium in the circuit just so you don't lose light when you stop.

David

[zebee]

If the motor is direct drive hub, then why have a dynamo at all? Just rectify the circuit, and include a parasitic buck/boost converter to drive the lights and charge a small battery... That would replace the dynamo entirely. Or you could just rectify the signal, buck/boost convert and drive the light without a battery at all. Your mechanical losses would go down too.

I don't know there are mechanical losses as the dynamo works by spoke magnets passing the sensor, so nothing mechanical in it.

My electrical knowledge is zero, so not sure what circuit where... wouldn't it be simpler to run them off the battery? Does it matter much if the battery power is going direct or via a circuit elsewhere? There are lights for running off electric bike systems already.

The dynamo isn't needed then, and you can get a constant voltage out of your system that way, regardless of speed - though I really would recommend a very small lithium in the circuit just so you don't lose light when you stop.

David

The lights I use have a capacitor so they stay on even if the wheel is not moving. If they are getting somehow the same style and amount of juice from the motor system as from the current dynamo then I could use the same lights.

The dynamo also has a USB charger fitting, I carry a USB power bank to charge phones/ipods/backup lights, charging the bank back up as I ride.


Zebee

[cj7hawk]

The lights I use have a capacitor so they stay on even if the wheel is not moving. If they are getting somehow the same style and amount of juice from the motor system as from the current dynamo then I could use the same lights.

The dynamo also has a USB charger fitting, I carry a USB power bank to charge phones/ipods/backup lights, charging the bank back up as I ride.


Zebee

Sounds like a pretty cool dynamo... What model is it? ( you have me curious )... If it's simple enough, then it's worth keeping just for that factor alone.

Regards
David

[zebee]

The lights I use have a capacitor so they stay on even if the wheel is not moving. If they are getting somehow the same style and amount of juice from the motor system as from the current dynamo then I could use the same lights.

The dynamo also has a USB charger fitting, I carry a USB power bank to charge phones/ipods/backup lights, charging the bank back up as I ride.


Zebee

Sounds like a pretty cool dynamo... What model is it? ( you have me curious )... If it's simple enough, then it's worth keeping just for that factor alone.

Regards
David

It's a Sunup Eco MaxiDyn 6V12W Bike Spoke Dynamo http://www.intelligentdesigncycles.com/ ... ynamo.html was my supplier. He also has an ebay shop. Good email communication.

You fit magnets on your spoke and the dynamo to the axle between hub and rear fork. I was not sure it was going to fit on the trike but fit it did. It's been in the rain and through puddles (the trike uses 20" wheels, anything attached to the axle is going to get up close and personal with puddles)

There is a USB female as part of the wiring which on the trike sits halfway up the frame between seat and BB, right near the water bottle. I plug the power bank in while riding (keeping it in the bag behind the seat) and charge that up, and power up anything USB from the power bank. I had problems with the Herman tail light, 2 of them blew with very little use. (they are connected to the Herman front light which is in turn connected to the dynamo). I have a B&M there now which is OK so far.

I don't notice any drag, at least no more than the SON hub dynamo on the other 'bent. Lift the trike's back end, spin the wheel, was no obvious difference with and without dynamo.

Sunup do one where USB is secondary to lights, that is you can power one or the other but not both and have to change cables. Cheaper but I figured I didn't want the hassle.