Viking eco power issue

1984danc

Pedelecer
Mar 29, 2020
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I've rigged up the multimeter and been for a ride. The voltage doesnt drop below 25v even up hill. The front wheel is quite tight to turn on it's own when everything is switch off. Is that normal? It's like the brake is binding but it's the front hub.
Forget that, front brake was binding ☺
 

Nealh

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Aug 7, 2014
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25v is getting low 3.57v per cell group, 22.4v (3.2v) is about the minimum to go.
If you see the same voltage in all power levels then it sounds like the controller is a speed controller which gives max current in all power modes with each one having a different max set speed.
 

1984danc

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Mar 29, 2020
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25v is getting low 3.57v per cell group, 22.4v (3.2v) is about the minimum to go.
If you see the same voltage in all power levels then it sounds like the controller is a speed controller which gives max current in all power modes with each one having a different max set speed.
So what you saying?
 

Nealh

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If it is a speed controller which it sounds like it is, they give batteries a much harder because they demand high current all the time. They reduce range by quite a lot.
 

Nealh

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You saying I need a new controller?
If it works then you don't need a new controller, just some controllers deliver power better in a more user friendly way.
 

Nealh

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Am I able to buy a universal throttle and simply plug it into my controller?
Only if the controller has a unused/ spare throttle connector.
You have to show us a pic of the controller and it's wiring in a way we can see all of it.
 

Nealh

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The two wire one is no use, it is likely for a brake sensor , only that three wire one is a likely candidate.
Makers name of the controller, Lishui possibly ?
Yellow is likely the signal with Black & Red logically being the Gnd & 5v, though a meter will tell you the later two.
 

Nealh

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It is a Lishui controller LSW831, the three pin wire connector should be the throttle then and wire order as I mentioned. But do check the Black/red with a meter to confirm there is polarity between them of 5v.
I thought it might be Lishui as the white data plug is usually a give away.
 
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1984danc

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Mar 29, 2020
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Ok so I've fitted a throttle to the bike. Works fine downhill and on the flat but just dies with any sort of incline!! This is the same as with the pedal assist. Do you guys think the motor might be knackered?
 

Nealh

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The ultimate power output is about 230w at the wheel at max current.
12a x 24 = 288w max output from the controller - inefficiency loss of approx 20% watts for the hub and you have about 230w max at the wheel.

You should feel the 230w helping out but sounds possibly like the battery isn't able to continuously supply the current under load.
 

1984danc

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The ultimate power output is about 230w at the wheel at max current.
12a x 24 = 288w max output from the controller - inefficiency loss of approx 20% watts for the hub and you have about 230w max at the wheel.

You should feel the 230w helping out but sounds possibly like the battery isn't able to continuously supply the current under load.
Definitely not the motor then?
 

Nealh

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Hubs don't often cause issues, if it rides ok on level ground then it is ok. The battery is the likely issue though without the bike in front of one we can only take punt at the issue, the power issue up gradients tends to lend it way to being a battery issue and one not in it's best youth.
 
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sjpt

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Jun 8, 2018
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Sounds like a battery issue as Nealh says. Earlier you said
I also tested them under load. One dropped to 27.1 and then other 27.9. I'm guessing from these results that the batteries are ok??
but you didn't say what sort of load. Load with the back wheel off the ground is trivial, and fairly small for gentle riding on the flat, but much bigger going up a hill.
 

Nealh

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Sounds like a battery issue as Nealh says. Earlier you said
I also tested them under load. One dropped to 27.1 and then other 27.9. I'm guessing from these results that the batteries are ok??
but you didn't say what sort of load. Load with the back wheel off the ground is trivial, and fairly small for gentle riding on the flat, but much bigger going up a hill.
A load can be simulated by lifting the wheel off the ground and applying the brake to a point that the wheel doesn't quite stop, measuring current or watts at this point will indicate the heavy load applied.
 

1984danc

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Mar 29, 2020
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Sounds like a battery issue as Nealh says. Earlier you said
I also tested them under load. One dropped to 27.1 and then other 27.9. I'm guessing from these results that the batteries are ok??
but you didn't say what sort of load. Load with the back wheel off the ground is trivial, and fairly small for gentle riding on the flat, but much bigger going up a hill.
Hi mate. Thanks for the reply. I had these results whilst out riding. Uphill, downhill on the flat and in all 3 modes, low medium and high. The voltage didnt drop below 27.1v no matter the incline or the mode. I've got 2 batteries and both the same results. Would have thought I'd be unlucky if both batteries were knackered!!