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Brown
Apprentice
USA
57 Posts |
 Posted - Jul 12 2007 : 8:03:23 PM
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Hello I am thinking of ordering this mini bike kit. It is designed for a gas engine, but I think an electric motor system would be much cooler. I intend to buy all the electronic parts at this electric scooter website.
Anyway, my big question is which electric scooter motor should I get(from this website)? Are any of them powerful enough? I realize I would have to change the motor sprocket to fit the kit's #35 chain and buy all the other electronic accessories.
My other question is should I buy a motor controller rated at the wattage of the motor, or above it?
Lastly, suppose I bought a 24VDC 200W motor and I had two 12VDC 10Ah batteries in series(24VDC 10Ah, right?). So 24VDC x 10Ah would give me 240Watt-hours. Does this mean I could run my scooter for about an hour?
Thanks. |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Jul 14 2007 : 11:14:11 AM
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| How fast do you want to go? How far? Hills? Off road? |
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Brown
Apprentice
USA
57 Posts |
Posted - Jul 14 2007 : 1:59:00 PM
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I would only ride my mini bike on streets/sidewalks. So I guess just moderate hills. I wouldn't go more than 6 miles at a time. I'd like to have a runtime somewhere near an hour. 15+ MPH.
I ditched that one website so forget about that.
I've been looking an different scooters and their motors. I was thinking of getting a 36V 1000W motor with 3 12V 28Ah batteries. The motor comes in a kit with a 100A controller and a Magura twist throttle. I know it's really expensive, but won't it be pretty powerful? |
Edited by - Brown on Jul 14 2007 2:01:52 PM |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Jul 21 2007 : 10:35:59 AM
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| That's actually a pretty decent setup. I suspect you will at times put the controller into overcurrent protection as a 1000W motor may draw several thousand watts at times. You should get decent range if you keep off the throttle, but 3 28AH batteries will be quite heavy. |
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Brown
Apprentice
USA
57 Posts |
Posted - Jul 28 2007 : 1:18:56 PM
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Alright, so I'm thinking of getting 3 19.68 lbs 26Ah batteries. As it turns out it's like impossible to find a 35 chain motor sprocket. I'll probably have to end up bolting on a 25 chain rear wheel sprocket. So suppose I had to use 25 chain. With the weight of the batteries, operator, motor and minibike frame would a 25 chain break? Would a heavy duty 25 chain work?
Also, where within the circuit do I put the fuse? Would a 100A fuse work? |
Edited by - Brown on Jul 29 2007 12:46:18 AM |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Jul 29 2007 : 10:32:46 AM
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#25 chain is probably too weak. Do you have a bearing supplier in town? They should be able to order any kind of sprocket you need.
At the minimum, the fuse should be between the battery and controller. 150A is probably a better value as it will account for some of the startup surge. |
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Brown
Apprentice
USA
57 Posts |
Posted - Aug 05 2007 : 9:11:08 PM
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I'll see what I can find, I might end up testing out heavy duty 25 chain first. The next question I have is about charging the batteries. I have a 12V 7A charger on hand. Can I hook all 3 batteries in parallel, or will that somehow put too much strain on the charger? Do I need a 36V charger? What charging configuration would you recommend?
Also I was thinking of making your 12V lead acid charger. I found a 12V transformer in my supplies but unfortunately I have no idea what the output current is. No indication. Any easy way to find it out with a multimeter? |
Edited by - Brown on Aug 06 2007 9:53:52 PM |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Aug 10 2007 : 11:18:45 AM
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You can put them in parallel to charge. I use the automatic battery charger on this site to charge my scooter and it's always worked well.
The only way to find out the current output of a transformer is to test it. Put an ammeter in series with a very low value resistor (1 Ohm) of high wattage and use it to short the output leads. |
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Brown
Apprentice
USA
57 Posts |
Posted - Aug 12 2007 : 01:06:40 AM
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| I have a quick question about your charger circuit. I'm having trouble finding equivalents to the BT136 triac and the BRX49 scr. Does it matter if I use sensitive triacs/scrs or just plain triacs/scrs? Right now I have a T106D1 scr and a L4004L3 triac. Both are sensitive but their IT(RMS) is listed at 4A and VDRM at 400V. Will these work? |
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Aug 12 2007 : 10:17:59 AM
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| Most generic TRIACs and SCRS with similar ratings to those specified on the circuit will work fine. |
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Brown
Apprentice
USA
57 Posts |
Posted - Sep 29 2007 : 6:27:49 PM
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Hi, I finished building my minibike over the summer and I just thought I should show the final result. I think it's awesome, thanks for your help. It's really fun to ride it at night because it's so quiet and stealthy and no one is around. Here are some basic specs:
top ground speed: -25+ (if it's fully charged)
downhill speed: -30+
freewheeling motor sprocket: 15 teeth
custom rearwheel sprocket: 70 teeth (25 heavy duty chain)
raw motor specs: 36V 1000W 2600RPM 32A
100A controller, Magura twist throttle, drum brake
3 12V 26Ah SLA batteries
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Aaron Cake
Administrator
Canada
6718 Posts |
Posted - Oct 03 2007 : 10:48:02 AM
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| Excellent work! What's the range? |
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Brown
Apprentice
USA
57 Posts |
Posted - Oct 06 2007 : 12:53:51 PM
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| Hmm I can't say that I know for sure. But, I rode it continuously for about 1:20 off of a full charge at varying speeds and it didn't lose any power. I'm really surprised with its overall performance. I'll just have to ride it some more to test its max. Glad you like it! |
Edited by - Brown on Oct 07 2007 01:36:18 AM |
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electric mini bike
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