4kw QS hub motor - More power

[MitchD]

I have just got my hands on one of these manufactured by ZHEJIANG TIANYING–



I am new to EV’s so I am really after a little advice to make sure I’m on the right track from what I have read on this forum already. From what I have been able to find out from the supplier the bike is fitted with a votol EM100 controller, 12” 4kw QS hub motor and 72V 30ah battery.

In the quest for speed I will be looking to buy a program cable to remove that pesky 50km/h limiter. Beyond this, I want to tweak some more settings. I’m not sure what cell/configuration the battery is made from, but it has a 100A circuit breaker on the side. Is worth pulling out the battery box out to peak inside? And if I do, what am I looking for to determine what current I should be pulling? It does say Model: JD72V30AH but it didn’t bring much up in a google search.
Also do the QS hubs motors have temperature sensors?

My initial goal is to be able to ride in an 80km/h speed zone for about 5 Kms on part of my morning commute. Hopefully achievable with the current hardware and if the battery can handle it, I would also consider going straight to a EM150 if the performance gains are there

Ultimately, I want to make this bike into a really fun machine to ride and hopefully learn about power electronic along the way. I think I would like to eventually upgrade everything to run a 12kw QS hub motor, but I’m pretty naive about what this would entail…

Any suggestions/comments welcome.

Bike + rider = 160kg

 

[jas67]

I have an Vespa with a 4kw QS hub motor and a 72v/38ah battery. (build thread here: https://endless-sphere.com/forums/viewtopic.php?f=10&t=109761 ).
It tops out at 100km/h, and cruises quite nicely at 80km/h.

It has a Kelly KMS7245 controller. If you can't change the programming on the controller on that bike, you could swap it out for
a KMS7245 and get the speed that you want.

https://kellycontroller.com/shop/kls-h/

The price for this controller is $179.

 

[j bjork]

The motor will probably be capable of a lot more.
The question is more what winding it is, if it is limited to 50km/h with a 72V battery it might be a very slow winding.
If it isn't I think you will come a long way with a controller upgrade and a battery that can deliver.
It looks like a short wheelbase, the motor would probably be capable of enough torque to flip over backwards.

The motors you buy from qs usually has a temp sensor, but you can check what wires you have. If you have a red, black, yellow, green, blue and white the white would be for the sensor. Measure between that and the black and see that you have a reasonable resistance.

As you say, first step is to try to program the votol that you have. The newer models seem to have became more difficult to understand the settings in, but you can find some info in the votol thred.

If you open the battery, try to determine what cells it is built of and how the connections are made to see if they can deliver some current. It will probably be some strange chinese cells, so it will probably be hard to say what they can do. You can always put some tough lipo cells in parallel to handle the current.

If you want a bigger controller maybe a votol EM150 would be something, or maybe far driver ND 72530(I think is) Or if you want more maybe ASI bac 8000 or maybe fardriver ND72850
Or if you want to go for higher voltage ND96850 or ND108850 :wink:

 

[QSMOTOR]

I have just got my hands on one of these manufactured by ZHEJIANG TIANYING–

Go Charged Moped.png

I am new to EV’s so I am really after a little advice to make sure I’m on the right track from what I have read on this forum already. From what I have been able to find out from the supplier the bike is fitted with a votol EM100 controller, 12” 4kw QS hub motor and 72V 30ah battery.

In the quest for speed I will be looking to buy a program cable to remove that pesky 50km/h limiter. Beyond this, I want to tweak some more settings. I’m not sure what cell/configuration the battery is made from, but it has a 100A circuit breaker on the side. Is worth pulling out the battery box out to peak inside? And if I do, what am I looking for to determine what current I should be pulling? It does say Model: JD72V30AH but it didn’t bring much up in a google search.
Also do the QS hubs motors have temperature sensors?

My initial goal is to be able to ride in an 80km/h speed zone for about 5 Kms on part of my morning commute. Hopefully achievable with the current hardware and if the battery can handle it, I would also consider going straight to a EM150 if the performance gains are there

Ultimately, I want to make this bike into a really fun machine to ride and hopefully learn about power electronic along the way. I think I would like to eventually upgrade everything to run a 12kw QS hub motor, but I’m pretty naive about what this would entail…

Any suggestions/comments welcome.

Bike + rider = 160kg

For this motor, it is no problem for Far driver YQ72180, this controller is higher than VOTOL EM100.
Below is the spec:

This is the link: https://www.aliexpress.com/item/1005002803162688.html?spm=5261.ProductManageOnline.0.0.50c14edfEOWRlX

And if you want 12kw, suggest still use 12inch 12kw, see this link: https://www.aliexpress.com/item/4001270136301.html?spm=5261.ProductManageOnline.0.0.50c14edfEOWRlX

This motor also can match with Far driver controller ND721200, which max speed can be about 130-140kph.

 

[MitchD]

Thanks for the replies

Jas67 – Super impressed by your build and have more hope now about what I can get out of the current motor!

J bjrok – thanks for the controller suggestions. Enough torque to wheel stand would be a nice problem to have…

I have gone back to QS to try to find out about the Kv of the motor, but it seems there are no identifiers on the outside.

I should have guessed it - my controller has a custom harness and my pin slots for the program cable were empty and glued over. Anyway, I have managed to connect and update the controller settings but haven’t been able to make any gains on the top speed –

These are my default settings:




I updated the mid and high speed values on page 2 all to 100% (shown below), this increased my top speed in 2nd gear to 47km/h and kept my 3rd gear still at 47km/h -


The controller seems to be updating fine. Does this mean this motor just has slow windings and all i can do is make small gains through increasing the flux weakening?

 

[j bjork]

Turn off HDC and test.
And read the votol thread before you make changes to the right flux settings.

 

[MitchD]

Thanks J bjork – I was thinking HDC was for brake regen for some reason, but you’re right, this was my issue.

I now top out at 55-60km/h with 0 flux weakening (speed 2)

And 80 km/h with flux weakening set to 3000 (speed 3) – which I now realise now is a little too high. I will reduce to 2300 and hopefully I’m not too far off 80km/h mark

Would love here anyone’s thoughts/experience on whether 3000 is pushing the flux-weaking too far for the hub and risk of de-magnetization

The flux-weakening compensation is set to 80, higher than recommended but this is the default value so I have left it as is.

I also increased by busbar current to 98A… Given I have a 100A breaker on my battery I haven't bothered to install a sport mode switch to over power



Seems like my battery is now the weakest link to increase power so ill start doing some research into that. Nissan Leafs are very common in this part of the world so I might investigate those a little more in preparation for a larger motor with increased Kv

If I added some LiPo’s to the current battery as J bjork has suggested would I still use the one BMS?

 

[j bjork]

If I added some LiPo’s to the current battery as J bjork has suggested would I still use the one BMS?

You have a few options in how to do it.
1: You can use the lipos in parallel with your battery, with no bms on the lipos and the bms you already have on the battery you already have. Then you wont be limited very much on the current your bms can handle.
But you have to monitor the lipos yourself to see they dont go out of balance, and make sure not to run them down too low in voltage.
I think that is more for testing, or once in a while. Not so much daily driver.

2: You can put a bms on the lipos so you have two packs with a bms each, then parallel them.
Then you can set a higher cut off voltage in the bms for the lipos so you dont risk running them down lower than 3,5V or thereabout.
Then you have a little limp home range left in the other pack.
If you get a problem with a cell in either pack it can only kill a cellgroup in that pack.

3: You can parallel the lipos with the pack you have, cellgroup for cellgroup and use one bms for the whole pack.
You would probably have to change bms to something that can handle the current.