a crazy, but possibly useful idea.

[robe]

Probably way too simplistic but here goes.

So you have an e-bike with a large motor but small battery. Not a lot of run time.

Smallish gas motor coupled to a modern car alternator should be able to hammer out quite a few amps at 12 volts. Now for the electrical wizardry. Step up the voltage and find a charger that will charge your battery at a high enough rate to make it usable.

My answer to perpetual motion. ( with the help of a little gasoline) Lol.

 

[ImpulseRocket]

Probably way too simplistic but here goes.

So you have an e-bike with a large motor but small battery. Not a lot of run time.

Smallish gas motor coupled to a modern car alternator should be able to hammer out quite a few amps at 12 volts. Now for the electrical wizardry. Step up the voltage and find a charger that will charge your battery at a high enough rate to make it usable.

My answer to perpetual motion. ( with the help of a little gasoline) Lol.

A typical car alternator can take up to 5hp to run.

 

[robe]

A typical car alternator can take up to 5hp to run.

That's what I was thinking. Or was it lack of? Ha.

I have a small 1200 watt generator that has a 79cc motor. Not a world of power, it will run a skill saw with low demand, no ripping and that is about it and weighs about 40 lbs.

So, way too simplistic. Back to Cloaked's idea of about 600 watts from a small motor.

 

[cloakedvillain]

This guy (yeseinstein) has a 500 watt front motor powered with a 38cc four stroke. Uses a highly modified car alternator.







A solar/sustainability channel did some experiments with car alternators and tread mill motors.







I have looked into this before and my solution was to use a permanent magnet brushless dc motor, then rectify the 3 phase ac you get from it to dc. You can buy three phase rectifiers super cheap, or make them yourself fairly easily. Some controllers can do variable regen, and that could work.

An arduino reading the voltage of the battery and the rpm of a honda/zenoah could use a pid loop to top it off. Haven't figured out the "cant charge and discharge at the same time" problem unless a lead acid battery is used.

Again, it is possible, just not economical.

 

[Wyvern]

A typical car alternator can take up to 5hp to run.

They sure do.

We have an old signboard with a not so small diesel engine, all it does is charge up the two 12V batteries with a car alternator.

 

[Wyvern]

This guy (yeseinstein) has a 500 watt front motor powered with a 38cc four stroke. Uses a highly modified car alternator.







A solar/sustainability channel did some experiments with car alternators and tread mill motors.







I have looked into this before and my solution was to use a permanent magnet brushless dc motor, then rectify the 3 phase ac you get from it to dc. You can buy three phase rectifiers super cheap, or make them yourself fairly easily. Some controllers can do variable regen, and that could work.

An arduino reading the voltage of the battery and the rpm of a honda/zenoah could use a pid loop to top it off. Haven't figured out the "cant charge and discharge at the same time" problem unless a lead acid battery is used.

Again, it is possible, just not economical.

The simplest way I know to have lithium cells and not need some complicated custom BCM is using a car or motorcycle lithium cell- they have a BCM in-built, so you could simply slam the battery with alternator current.

 

[cloakedvillain]

Not sure those swap in batteries can be run in series. I would have to look in to that.

This is all just a thought experiment. We have to come back to these important questions.

What kind of build do you want? And why does it have to he a hybrid?

I can't argue with the rule of cool, but if you want the pedal assist system, that can be done without the hybrid aspect.

And if you want twist and go with great mileage, a 150cc scooter is going to be a cheap and useful option.