Battery for motorized bicycle

Akutey

Member
Joined
Dec 10, 2018
Messages
48
Your only good source of power will be that 12v generator. 24ohm load at 12V you should have 500milliamps @ 6Watts. Should do the trick for trickle charging a small motorcycle battery or have better luck with a couple 12v NiMH battery pack that prefer trickle charging. Or better yet have it regulated and connected for a single accessory. Even a super bright LED will push its draw. Its not like you can charge and discharge a battery at once. You need to have alternator to produce the power demand. Bicycle dynamo arn't the greatest and has been tried in conjunction with the 12v gen and does not produce an appropriate amount of power for the applications wanted. If you want a CG with a robust electrical system use a motorcycle battery and charge it when parked. Unless your running speakers and an amp or high beam headlights you should be worn out from riding before it drains.
 


Will'smotobikes19

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Joined
Apr 9, 2018
Messages
1,440
This motor has electric and pull start and is affordable. I have the same thing only older. I just tested the starter today for the first time and it worked great. It will fit a bikeberry friction drive kit, staton inc. friction drive kit, the staton inc. chain drive kit, bikeberry axle mount kit or the golden eagle bike engines kit. May be some others. To avoid spending alot you can build a mount for the auto clutch yourself. This is legal engine size is most areas but I think you're from Europe because you said your English was bad? so idk. https://www.ebay.com/itm/Alu-49cc-Piston-Engine-2-Stroke-Single-Cylinder-Pocket-Bike-Motorcycle-Air-coole/253678401103?_trkparms=aid=555018&algo=PL.SIM&ao=1&asc=57159&meid=a101debe517b404ab8d2c64431c30c20&pid=100005&rk=2&rkt=12&sd=183068481617&itm=253678401103&_trksid=p2047675.c100005.m1851
 

Spare_Parts

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Joined
Nov 29, 2017
Messages
1,190
This motor has electric and pull start and is affordable. I have the same thing only older. I just tested the starter today for the first time and it worked great. It will fit a bikeberry friction drive kit, staton inc. friction drive kit, the staton inc. chain drive kit, bikeberry axle mount kit or the golden eagle bike engines kit. May be some others. To avoid spending alot you can build a mount for the auto clutch yourself. This is legal engine size is most areas but I think you're from Europe because you said your English was bad? so idk. https://www.ebay.com/itm/Alu-49cc-Piston-Engine-2-Stroke-Single-Cylinder-Pocket-Bike-Motorcycle-Air-coole/253678401103?_trkparms=aid=555018&algo=PL.SIM&ao=1&asc=57159&meid=a101debe517b404ab8d2c64431c30c20&pid=100005&rk=2&rkt=12&sd=183068481617&itm=253678401103&_trksid=p2047675.c100005.m1851
Nobody cares so get lost. He has a cg.
 

Herman Klutz

Active Member
Joined
Dec 25, 2016
Messages
150
I believe an off motor generator to keep a battery fully charged is a better option. Going on this contraption, https://www.popularmechanics.com/technology/gadgets/how-to/a10245/pedal-power-how-to-build-a-bike-generator-16627209/
Those type generators are cheap and generally weatherproof, also available in compact sizes. Wheel powered or with a belt and pulley??? The system would require a generator, a regulator to control the output, a sealed lead acid battery, some wires and way to turn it.

Someone smarter than I am should be able to concoct a simple set up that could run in either 6V or 12V.
 

Herman Klutz

Active Member
Joined
Dec 25, 2016
Messages
150
The second video should be fairly easy to duplicate. The generator is a common one found on eBay, I know I have seen it there but has been covered with an aluminum cover. I believe the "wiring jig" he added is a pit bike voltage regulator. The bracket he used to hold that on came from the electrical dept at Home Depot. it is called a "EMT conduit pipe hanger" The pulley he added, there are a thousands of sources, ebay is the easiest. The generator bracket is fabbed out of sheet metal. I am fairly sure this generator is the same one. https://www.ebay.com/itm/12-24V-30W-CW-CCW-DIY-Generator-3000-6000RPM-High-Speed-Permanent-Magnet-Motors/254177964352?hash=item3b2e2ff140:m:md_zVvUFMkhKveYZw_C8mJw

I saw the wiring diagram for the pit bike on some forum, not sure where, but I may have it in my notes. I will look for it, but I believe it came from the link that was posted in one of the prior posts from the other motorized bicycle forum.
 

Steve Best

Well-Known Member
Joined
Sep 22, 2012
Messages
1,228
I haven't dug into this yet, but I do have a lot of experience with getting full motorcycle electrical functions out of an Enduro bike with only 40W output.
87012

So, headlight and taillight are powered by 12v AC directly off the charging coil which has a 12v (14.7v AC) voltage limiting shunt regulator to limit the voltage. There is a second 12v DC circuit that powers a battery, the blinkers, horn and a small LED safety bulb in the headlamp housing (in case I dump the bike at night and the engine dies. The battery is 8 NiCads taped and soldered together. Weighs about 1 lb. Li battery would be wonderful.

So, my dream is a hybrid bike weighing under 50 lbs with a China Girl supplying speed, range and charging when I need it, and a 250w electric supplying 20mph city/parkland/bikepath power to not offend the population. All I've done so far is build a few CG and electric bikes, but not combined them of got the CG charging.

The flywheel turning 6000+ rpm is a great potential for power, but we know tapping it off the present coil will kill spark or timing (and power). Options are:
  • Use more powerful magnets on the flywheel (glue on rare earth magnets?)
  • Use a separate coil for charging off the flywheel, ideally at 90 degrees to ignition coil
  • Use a discrete coil and glued on magnets in another location (wheel rim? Clutch housing?)
The goal would be to charge a LiFe battery in 20 miles that would run the electric motor for 5 miles or similar.
I believe at all times keep the weight down, keep it simple and remember that this is at heart an assisted pedal bike.

I really think the China Girl has the advantage for a lightweight durable power source with a bit of prep.

I should mention: if you are cutting the laminated coil core or flywheel magnet be aware the sheets of the laminate are varnished to insulate them. This is to avoid eddy currents, heating and improve efficiency. Cut slow (no grinding), keep cool and re-varnishing might help.
 
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