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5kW hub drive motor! (Washing machine DIY E-bike)

Vikingimike01

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Jul 1, 2018
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1,241
Hello! Back. I have everything on the bike fixed, and installed, other than:
Battery, controller, pedal assist sensor, alarm

I have a small problem with the battery. It's very big, oof. It's a 30 Ah 72v pack made from 2 different 15ah 72v packs wired in parallel. It's too big to fit in the frame. I can either put it on top (men's bike) or make like a rack on the back. The controller fits in the frame.

Where do I put it now?
 


bakaneko

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Nov 16, 2015
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1,435
glad everything arrived in tacked. If you don't have the tools, I would hold off on the pedal assist sensor for now until you get a sense of how powerful the motor is going to be at the different PAS levels. 5kW rated is what 1kW-2kW-3kW-4kW-5kW levels? I mean I don't know what it might be 1kW is no joke from a dead stop; might be hard to control. For big battery packs I've seen guys just mount it on the top tube on either side. A picture would help to get a sense of things. Also, keep the wires to both packs the same length.
 

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Vikingimike01

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Jul 1, 2018
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yeah i did that. Anyways. I may have to mount it on the top tube

Its raining a lot here this week so cant really work on it
 

Vikingimike01

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Jul 1, 2018
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Yes indeed. It has a 120 amp controller. Multiply by 72v nominal voltage, or 84v fully charged, you get wattage. Around 14 horsepower i belive
 

Vikingimike01

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Jul 1, 2018
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Hey guys! I am having problems.

I set everything up on the bike. It came to installing the batteries. I used 2x 72v battery packs wired in parallel. Okay.
I wired everything up. Plug in the battery, i see huge sparks at the plug, and then hear a huge pop from inside the controller. And it doesn't start, nor do anything. What happened? It's supposed to be a 72v 120amp controller...
 

bakaneko

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Nov 16, 2015
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Just checking. You double checked the wiring diagram and tested the final battery connectors with a multimeter to confirm the right wiring? Sometimes, the chinese electronics have weird wiring.
 

Vikingimike01

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Jul 1, 2018
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weird wiring... Ahh i didnt check the battery but it seems to work correctly. Do you want a picture of the wiring? Could I blow the controller by having the negative and positive reversed? Probably didn't do that but still...
 

bakaneko

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Nov 16, 2015
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1,435
Do you have a multimeter? This is essential to just ensure everything is correct. I have a lot of wiring on my ebike generator hybrid and before plugging everything in, I test each new connection from the battery/generator sequentially to ensure everything is wired and voltage is correct. I saved myself a few times doing this.
 

Vikingimike01

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Jul 1, 2018
Messages
1,241
I do, but its not digital. Just like the one you can use to test voltages and thats about it. What do I do now?
 
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