E-Bike Tandem Electrical Problem - Please Help!

Steve360

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My first E-bike (Tandem) build has me banging my head against the wall, it looks great but doesn’t go. Please help me someone. I built it using parts from a Chinese electric scooter and a traditional 26 inch bike. I am a competent mechanic and auto electrician when it comes to classic cars, but speed controllers and BLDC motors are all new to me. While I think I understand it, I am definitely missing something.

I’d really appreciate some guidance from you E bike & Scooter enthusiasts out there.

I’ll try to explain briefly what what I have created. I have a 48v 1400w BLDC hub motor with a 48V 1500w speed controller, powered from a 48v 100Ah Lithium-ion battery and the standard Chinese scooter twist throttle.

From the battery, I have a Pos & Neg going to the Pos & Neg on the Controller. I have bridged the key switch wires from the controller (Red & Orange). I have connected the Red/Black/Green to the Red/Black/Green of the throttle. I have connected the Yellow/Blue/Green phase wires from the controller to the corresponding phase wires on the motor. Finally the Red/Black/Yellow/Blue/Green hall wires from the controller to the corresponding hall wires on the motor. But I have no life from my machine.

First I bought a new controller thinking this was the problem, but it’s still the same. I then recently I bought an E-Bike testing device. With the new device I have perfect test results from the throttle, motor phase and hall sensors, all shows up good. The only negative result was the controller, when tested, doesn’t light up the 5V output LED. I then tested the 5v output with a multi meter and I am only getting an output of 2.76V. Which in return from the throttle when ‘closed’ reads .82v and ‘fully open’ reads 1.98v. So my question is, should the motor turn slowly with this low voltage or is it normal that it doesn’t turn at all ?

Thanks in advance to everyone reading this. Steve.
 
Hi Motley,
The guide looks very complete. I just need to study it, understand it and go back to the Tandem to see if it gives me any clues.
Thanks very much, Steve.
 
My first E-bike (Tandem) build has me banging my head against the wall, it looks great but doesn’t go. Please help me someone. I built it using parts from a Chinese electric scooter and a traditional 26 inch bike. I am a competent mechanic and auto electrician when it comes to classic cars, but speed controllers and BLDC motors are all new to me. While I think I understand it, I am definitely missing something.

I’d really appreciate some guidance from you E bike & Scooter enthusiasts out there.

I’ll try to explain briefly what what I have created. I have a 48v 1400w BLDC hub motor with a 48V 1500w speed controller, powered from a 48v 100Ah Lithium-ion battery and the standard Chinese scooter twist throttle.

From the battery, I have a Pos & Neg going to the Pos & Neg on the Controller. I have bridged the key switch wires from the controller (Red & Orange). I have connected the Red/Black/Green to the Red/Black/Green of the throttle. I have connected the Yellow/Blue/Green phase wires from the controller to the corresponding phase wires on the motor. Finally the Red/Black/Yellow/Blue/Green hall wires from the controller to the corresponding hall wires on the motor. But I have no life from my machine.

First I bought a new controller thinking this was the problem, but it’s still the same. I then recently I bought an E-Bike testing device. With the new device I have perfect test results from the throttle, motor phase and hall sensors of e bike, all shows up good. The only negative result was the controller, when tested, doesn’t light up the 5V output LED. I then tested the 5v output with a multi meter and I am only getting an output of 2.76V. Which in return from the throttle when ‘closed’ reads .82v and ‘fully open’ reads 1.98v. So my question is, should the motor turn slowly with this low voltage or is it normal that it doesn’t turn at all ?

Thanks in advance to everyone reading this. Steve.
I am in the process of putting together and kicking off a conversion project to electrify our tandem. I have been doing a lot of research and have spent a fair amount of time running simulations on the ebikes.ca website and have narrowed down to a specific motor, battery plant, and controller.

This is not a "what do I need" or "how do I choose" thread. I am interested in others experiences and lessons learned either electrifying and/or owning and riding an electric tandem. I realize the population is small here, but this is one aspect that really isn't covered elsewhere on the interwebs (that I have been able to find) and this is where folks in the know hang out.

I would be interested in some details of your setup (voltage, battery plant, etc.). How you ride (electric assist all the time, hills only, etc), what kind of range do you get from your setup, and finally, what you learned and what you would do again or differently if doing it again?
 
I would be interested in this too. I have a Burley tandem that should make a great platform as it has a nice strong and rigid frame.
One question I would have is finding a controller that would be fast enough.
As a pure analog bike two moderately strong riders have no problem hitting 30mph at a reasonable cadence. We have hit 50mph on a downhill.
Can I find a controller that I can set to 40 or even 50mph as a maximum?
 
Hi Finchlean.
I'm sorry, but I can't really answer your questions as I haven't used it yet.
Good luck with your conversion.
Steve.
 
Just a shot in the dark but have you checked brake cut off switches. If your brake lever is open even a little you get nothing. It has happened to me more than once. Also alarm wires? The learning leads? Put together them take apart to change phase rotation. Just trying to help.
 
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