agniusm
1 MW
Need advice on hubmotor, small one to connect to pedals for two to pedal and charge the battery. Also need a controller with variable regen. What wattage do you think is optimal? 500W?
Hub motor as generator
- Thread starter agniusm
- Start date
Drunkskunk
100 GW
Well, you're not going to be able to put 500 watts into a generator with pedal power for more than a few seconds. 100 watts is still going to be a real workout. A 150 watt rated motor would be overkill but maybe useful if you want to loan the bike to Lance Armstrong.
Hub motors aren't efficient, as far as motors go. Look for a high RPM motor, something like an RC motor.
agniusm
1 MW
Hence variable brake so I could controll regenerative force to allow charging for single person or for two. We are talking about what, 80% efficiency, sure I'd like more but this seems simple enough system. So perhaps 250w motor should be good.
You might consider a geared motor, run backwards, wound such that at it's normal operating speed it puts out a much higher voltage than you need...so that even when you are not moving it fast, you can still get enough voltage out of it to help with charging.
The gearing may eat up a tiny percentage of teh input power, but it would let you run the motor faster at lower pedal speeds without large external chainrings.
I don't know if there is any information useful to you in these other topics about hubmotors as generators:
http://www.endless-sphere.com/forums/search.php?keywords=%22Hub+motor+as+generator%22&terms=all&author=&sc=1&sf=titleonly&sk=t&sd=d&sr=topics&st=0&ch=300&t=0&submit=Search
The gearing may eat up a tiny percentage of teh input power, but it would let you run the motor faster at lower pedal speeds without large external chainrings.
I don't know if there is any information useful to you in these other topics about hubmotors as generators:
http://www.endless-sphere.com/forums/search.php?keywords=%22Hub+motor+as+generator%22&terms=all&author=&sc=1&sf=titleonly&sk=t&sd=d&sr=topics&st=0&ch=300&t=0&submit=Search
agniusm
1 MW
Thanks Awolf. Read those, most were no use.
48V or 72V system. Have not decided yet, depends what motor i choose.
I want the system to work as pedelec, but without power input. Say i want to drive, i spin the cranks but without effort. If i want to charge my baterry, i turn the knob to desired regenerative braking level and start putting some effort and charge the battery. Its combined system i am thinking about with solar charging on the vehicle to also comply with pedelec regulations here in EU.
At this early stage i can put about 750W of solar on the roof of a vehicle.
My thought was to measure my cadence with bike computer with magnet on the front sprocket, then gear motor to optimal (most efficient) rpm and controll regen as i like. I know efficiency will suffer, but i'd like to try a system that will need as little plug-in as possible
48V or 72V system. Have not decided yet, depends what motor i choose.
I want the system to work as pedelec, but without power input. Say i want to drive, i spin the cranks but without effort. If i want to charge my baterry, i turn the knob to desired regenerative braking level and start putting some effort and charge the battery. Its combined system i am thinking about with solar charging on the vehicle to also comply with pedelec regulations here in EU.
At this early stage i can put about 750W of solar on the roof of a vehicle.
My thought was to measure my cadence with bike computer with magnet on the front sprocket, then gear motor to optimal (most efficient) rpm and controll regen as i like. I know efficiency will suffer, but i'd like to try a system that will need as little plug-in as possible
