My voltmeter/throttle shows voltage when I pedal without battery, does this mean I could have regen?

Tiao

100 µW
Joined
May 26, 2022
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Hello! I'm new but I'm really excited to be here! Been lurking this past month I finally built my first ebike with a used rear motor 36v 350w, a controller that came with the motor that is 36v 16a and two hoverboard batteries which I swap (one to get to work and one to come back home).

I noticed my voltmeter reading tension when I pedal and I'm wishing so bad for my no name controller to support regen, mainly for braking. I couldn't find anything about my controller online.

The display is connected to the positive power input on the controller
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Here is a short video showing some action.

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In the linked image there's the other connectors first one is orange and yellow (no ideia what it does), second and third are purple and yellow (are these the brakes?), forth is black and red(no idea), fifth is blue and black(no idea). I could measure the voltage output on each wire if it helps.
Thanks!
 

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video link didn't work. says "private".

For regen to work, you need a controller that supports it, and a direct drive motor. Can you confirm the latter, since the link doesn't work. Also, can you describe what you mean by "tension". Normally, for regen to work, you need to trigger it via a brake lever switch, but by your description, it doesn't mention you had the "tension" when engaging the brakes (brake switch), or just when pedaling. Direct drive motors have drag when pedaling without power, and that might be the "tension" you are experiencing. If so, it's still possible that your motor and controller support regen, but likely not what the "tension" is.
 
Thanks! I'm gonna see what's up with the link.
Tension is a way to say voltage in Portuguese.
The video should work now!
 
Shoot! Just tested shorting the brake connectors and throttle just doesn't work, didn't feel any braking. I guess that's that
 
Tiao said:
Shoot! Just tested shorting the brake connectors and throttle just doesn't work, didn't feel any braking. I guess that's that

Did you test while riding? Regen on a cheap controller usually doesn't bring a bike down to zero speed. The bike needs to be going at least 7 or 8 miles an hour to work.
 
Did you test while riding? Regen on a cheap controller usually doesn't bring a bike down to zero speed. The bike needs to be going at least 7 or 8 miles an hour to work.

I didn't, going for a ride to test it!
 
Yep, guess I'll have to change the controller for this. But not now, Thank you very much @E-HP !
 
Spin the whee. If you feel more friction in the reverse direction (you may hear the gears turning) then it's a geared motor. No regen possible. If it feels the same in either direction, then it's direct drive.,
 
Really? Here I'd been imagining that geared hubs coast freely, since almost all of them have freewheels. A little envious as my direct drive with regen creates a small but noticeable core loss drag.
 
donn said:
Really? Here I'd been imagining that geared hubs coast freely, since almost all of them have freewheels.
They do, more or less. Unless something goes wrong with the clutch, and it jams or gets "sticky", it won't pass wheel rotation back thru the gearing into the motor, so the motor won't spin from wheel rotation, in the forward direction.

But if you reverse the wheel rotation, the one-way clutch is now "locked" and it does pass the wheel rotation back to the motor. It must be able to do this because if it didn't, then the motor couldn't pass it's rotation thru the clutch into the wheel in the forward direction. ;)
 
Most 350 w rated motors are geared type motors. So no regen possible, unless you got one with the clutch locked, or jammed up. Dont spen money on a controller with regen, if your motor is not compatible with regen.

If the resistance gets harder rolling the wheel forward than backward, the clutch is working. Try this with the wheel off the ground, or the bike upside down.

We are not talking about the freewheel gears on the outside, but an internal freewheel, or clutch, inside the motor. So with a geared motor, when you turn the wheel backwards the outside freewheel will turn freely, AND the internal one as well. But you feel resistance when turning it forward. This resistance will be very light when turning the wheel slowly. Spin it fast to feel the motor resistance.

Regen is a cool idea, but its most effective on vehicles the heavier they get. This is why mine dump trucks bigger than a house have regen. But bikes are very light vehicles, so the benefit of regen is a very small number of watt hours. To get the same benefit on a 20 k ride, pedal or coast from time to time, with the motor off for a kilometer total. Its just not much energy saved. The better coasting of a geared motor can save just as much power.
 
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