My wattmetter only shows the voltage

cwah

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Jun 3, 2011
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Hello there,

This is the first time I plugged my wattmeter into my e-scooter. And when I put the motor on, there is only the voltage that varies. Other indicators remain to 0:
[video=youtube;oGq35Tg1L9Y]http://www.youtube.com/watch?v=oGq35Tg1L9Y[/video]

Is it normal? Shouldn't the Wh and Ah displayed instantly?

Also, I've way too long cables from the ESC, but these cables don't are just connected to the throttle:


Do you think it's ok if I just leave the cables as it is?

Thanks a lot
 
D

Deleted member 4366

Guest
Looks like you got the battery and controller on the wrong sides of the meter.
Source is the battery and load is the controller.
 

cwah

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But I already tried to reverse the pluggin polarity.

When I do it the wattmetter doesn't start at all. I don't see where else I can plug the wattmeter.
 
D

Deleted member 4366

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But I already tried to reverse the pluggin polarity.

When I do it the wattmetter doesn't start at all. I don't see where else I can plug the wattmeter.
I'm not sure what you mean by polarity.
Have you tried plugging in the battery to the side that says "source" and the controller to the side that says "load" - yes or no! If the answer is yes, was there any display?
 

wurly

Esteemed Pedelecer
Aug 2, 2008
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Yeovil, Somerset
Looking at the video and the photos, i would agree with Dave, they are around the wrong way. You shouldn't have damaged it, but i would recheck your connections
 

cwah

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I don't know where I should look to find "source" or "load". There is nothing written on the controller.
 
D

Deleted member 4366

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If you look at the wattmeter with the numbers the right way up, the battery should be on the left side and the controller on the right. Normally the wattmeter is marked " source" to the left of the screen and "load" to the right of it so that you know where to connect the battery.
 

cwah

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Ok, I just did that.

When I put the batterie to the "source" and controller to the "load" side, the wattmeter screen is blank and there is nothing displayed.
 
D

Deleted member 4366

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When connected that way, are the wires still red to red and black to black?
 

cwah

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Jun 3, 2011
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I think I've found what I did wrong..

I soldered the connector on the wrong side. The red are connected with the black...


I'll have to cut all of this and solder new set of connectors... Do you know if I can recycle these connectors? I already soldered them and clipped them strongly inside the plug.
 
D

Deleted member 4366

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If you can get the plastic covers off, you only have to heat them up with a soldering iron and pull them off with pliers, otherwise, cut them off and start again.
 

cwah

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Jun 3, 2011
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No smoke wurly, I resoldered everything and it's finally working!!! Thanks guys!!

[video=youtube;6XquvPZaT58]http://www.youtube.com/watch?v=6XquvPZaT58[/video]

Still not sure how to read that. So I use between 1.5 to 3 A? and between 33 and 66W? Is it good?
 

wurly

Esteemed Pedelecer
Aug 2, 2008
501
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Yeovil, Somerset
Your meter will show
Real time Amps (top left)
Real time Volts (top right)
Real time Watts (bottm right)
At the bottom left you getting a scrolling display
Vmin (showing how much volt sag your battery gets during use)
Ah ( amperes used per hour)
Wp (watts peak, how much peak power your meter read during use)
Wh (Watts per hour used, very useful for judging power left in a battery)
Time (per use)
Everything gets reset when you disconnect
(Watts = Volts X Amps)
so by using 3A at 22V would give you 66Watts, so your meter survived and is still working ok

I should also add, that these meters although good value aren't calibrated very well, so don't expect accurate measurements especially current drawn(amps)
 
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cwah

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Jun 3, 2011
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Thanks for the answer Wurly.

My battery is a 17.5V 8AH. So a total capacity of 17.5*8 = 140 WH

When I see 66 Watt on the bottom right, I should conclude that in 1 hour I'll have 140 - 66 = 74 WH remaining?

So I can theorically use continuously my battery for 2 hours?
 
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D

Deleted member 4366

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When you're riding on it, the current (and hence the watts) will be much higher. You have 140wH -thats right. Ride the scooter for 5 minutes and see how many wHs you've used, then you can divide it into 140 to see how many 5 mins you have. My guess is about 15 to 20 minutes.
 

cwah

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You're right. Nothing is better than field testing.

I'm going to try that tomorrow :)

ps: And by the way, does it matter to have long servo cables? I suppose only long battery cables would diminush the max distance. I suppose longer cables to throttle or servo should not be a problem?
 
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cwah

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I just tried the motor this morning, it runned for a hundred of meters and suddently there was a huge drag on the wheel.

Motor is still working but it seems that something is inside:
[video=youtube;aGgBa5SOOlM]http://www.youtube.com/watch?v=aGgBa5SOOlM[/video]

Can you hear the squeaky noise? And the huge drag to move the wheel? I can't see anything preventing the wheel or motor to move properly.

Any idea what could cause that?
 

cwah

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Jun 3, 2011
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Thanks, what should I do to repair it? I'm a clueless about bearing.