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Showing off my functional Parallel Hybrid, and a question too.

Hello. I bought 2 Wilderness Energy BD24 motors and a bunch of spare brushes on Ebay, then a SP24750 and throttle from ESP. I'm going short-story this to say I have built a working Parallel Hybrid Bicycle.


The rear wheel is powered by a Golden Eagle Bike Engines belt-drive with a Tanaka Purefire 32cc 2-stroke. This is a clean engine with a real catalytic converter, 1.5HP, and it drives the bike (with low gearing) at about 20mph, level.


The front wheel is one of the 24V 500W hubs mentioned above, and it will drive the bike at about 14mph, level.


I use these particular power levels because they are legal without documentation in Oregon.


Together, the 2 drives will pull a decent 6-8 percent grade, at about 18mph, and with my pedaling along I can slowly climb the 10+ grade that is my street.


Using two DPDT relays, a DROK brand CC/CV Boost Converter set to 27.2V 5A output, and a push-button on the handlebars to activate the relays, I can completely isolate the motor-controller, and then recharge the battery-pack while using gas power or going downhill at anything over 15mph. This all really works, I can ride along the very hilly Rt 101 for as far as I'd like, and arrive at my destination with enough battery to do the same on the return trip.


I'm attaching a picture of the bike, and a view inside the "box."

image


image

the relays are on their sides so that bumps don't turn things on and off.


Now for the question: I'd like to try to get a wee bit more power out of the front hub. I don't actually need any more speed. The hub has drawn a recorded maximum of 800W and 33A as shown with a RC Analyzer. What would be the difference between over-volting to 36V or simply getting a higher-rated 24V controller? In other words, can I "force" the motor to be more powerful by upping the volts, or will it just "become" more powerful by making more Amperage available?


Thanks in advance for any input (pun intended)

as I cannot edit, or cannot see how, I am adding this comment. i now have another battery pack, on the rear rack, in parallel, and I carry an available 40Ah of 24V, and the available combined current is 80A continuous.


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Thanks for sharing your custom built hybrid gas-electric bicycle with us. What a great idea and build.

Installing a new controller with a higher Amp rating than the existing one will increase the torque output of the motor without increasing its top speed.

Installing a 36 Volt controller and increasing the battery pack to 36 Volts to overvolt the motor will increase the torque output  and top speed of the motor.

Both of these methods will create a situation where the hub motor would run hotter than it was designed to if the over Amped and or over Volted motor was run at full throttle for an extended period of time though so I would watch the motor temps for a while after installing a more powerful controller to make sure that the motor does not overheat and burn out.

very good. clearly, it's easiest to just get a more powerful 24V controller, which is what i will be doing. as i mentioned at the beginning of my post, i have an entire spare new motor and extra brushes, so i've not been afraid to do a little experimenting. these old WE hubs have been known to handle 48V, so I'm pretty sure this one can handle a few more amps. my biggest concern has been how are the brushes holding up to being used for charging? only time will tell on that one. thanks very much for your quick and on-point response.

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