advice for beginer

[Jacq]

Hi all,
just asking for an advice.
I have pleced the order for Mxsus V3 6T, rims 19"x2.15, I am thinkig about the Adaptto Mini E. battery 20s8p lion. To wotk is about 17 km ( 35 in total + stop in pub after work mostly flat I am 100 kg
Is is a right set up for that rider ?

 

[markz]

I wouldn't have gone with a 6T, especially if you were building from scratch. A 3T would have been a waaaaaaay better choice.

Will you be using a BMS?
What battery charger do you have?

According to Justin's data, Teslanv get the following phase current limits on the various windings:

MXUS XF40-45H "3000W" Direct Drive Hub Motor Series:

3T:
Max. Continuous Phase Current: 55A
Overheat in 10 Minutes: 85A
Overheat in 60 seconds: 242A

4T:
Max. Continuous Phase Current: 42.6A
Overheat in 10 minutes: 66A
Overheat in 60 seconds: 186A

5T:
Max. Continuous Phase Current: 34.9A
Overheat in 10 minutes: 51.6A
Overheat in 60 seconds: 150A

6T:
Max. Continuous Phase Current: 30.3A
Overheat in 10 minutes: 47A
Overheat in 60 seconds: 132A

Generic Winding Phase Current Limits per strand:
Max. Continuous Phase Current: 2.84A per strand
Overheat in 10 minutes: 4.4A per strand
Overheat in 60 seconds: 12.4A per strand

 

[Jacq]

Hi,
I do not have any charger yet, Just placed the order for motor in China and placed the order for moped rims 19"
What is wrong with this motor, I though that I am heavy so that why I am thinking about slow but stronger motor.

 

[markz]

For one, with your 6T motor to get the same speed as a 3T you need waaaay more voltage.
Which means you need a controller that can handle the higher voltage. That is more money.
Another is the quote I listed in my previous post. The amperage is quite low on a 6T compared to a 3T.
But dont be fooled, the motors are exactly the same and will provide the same power. Its just a matter of how you get there.

But for heavier people like you and me, and others here on Endless Sphere - a lower tooth count=higher kv motor would have been an ideal choice. You chose right in going with a smaller wheel diameter. That gives you more torque, compared to a 29" or a 26". The 3T has thicker shorter wire, which makes it handle more amperage.
While the 6T has thinner longer wire, which makes it handle less amperage.

Dont worry if you are confused, I was. But I have been sold on the lower tooth count = higher kv direct drive motors. I asked a lot of questions when I bought my 4T MXUS 3000W V2 motor. I just about bought a 6T motor, but I lucked out and went with a 4T based on people, like John in CR, telling me what they ride.

One thing to note, since you got the 6T, with the smaller diameter wheel....you are going to go even slower now.
No big deal mate. Live and Learn. You could just sell the 6T and break even. People will love the fact you live in Ireland and hence a quicker shipping time to Europe. Then you can order a 3T motor which will be an excellent choice for you.


Did you play around with ebikes.ca motor simulator?
http://www.ebikes.ca/tools/simulator.html
For the motor, on the first scroll down, scroll all the way down and click Show All.
Then choose MXUS 4506, then you can see what the differences are, somewhat.

 

[nutnspecial]

I guess it all depends on what speed and power level jacq is shooting for.

For best torque curve on a hub at a lower speeds, you either need an increasingly smaller wheel to put it in, or also start dropping kV, right?

 

[Jacq]

Well, I am not going to break any speed records, but it would be nice to get work in the morning before a tea time
Thank you for the advise, the motor never came yet so I'll ask Ms Ann Woo whether it is possible to swap for different version of this hub motor if not I will ask for another one and sell the 6T.

 

[nutnspecial]

I'm curious, do we know the kV of the different mxus's?
What top speed are you shooting for Jacq?

I'm assuming 6t, 20s, and a 19" mx tire should be good for about 40mph, which would obviously mean more torque/efficiency 0-40mph than a similarly powered 3t that might hit something like 55mph, right?

 

[Jacq]

I'll be very happy of the top speed 65km/h=40mph I ges. So I thing that has to give it the 20s battery (74 v)+ 8p ? Sanio 3.5 Amp 3C

 

[nutnspecial]

To find out if 20s is a good match we need to know the kV of the different mxus motors, especially the 6t one you are thinking of or have already bought. 40mph is just an educated guess on my part.

As far as current from the battery: 8p of 3.5ah is <30ah total, and 1c to 3c draws would be 30-90a. I'd talk to the seller to get an estimate of peak and continuous amp draws- likely the bms will dictate those.

 

[nutnspecial]

Btw Jacq, I noticed you've posted in the 'e-vehicles section'.
You will likely get more replies/help if you ask a Moderator to move your thread to 'ebike section' or 'hub motor section' !!

 

[markz]

What are your riding conditions? Flat, Hilly, Mountains, Traffic, Distance, Stop lights




6T is about half the KV of a 3T motor.
Which means, that in order to get the same speed you need to double the voltage.
But like I said, its all a balancing act because it will produce the exact same torque, just a matter of how you get there.

This is a quote that I searched. I believe its from TeslaNV's MXUS 3k V3 Turbo for sale thread.

Nominal Wattage: 3,000W
Peak Wattage: 6,000w
Voltage: 48V-96V
Torque Constant (Kt): 3T = 0.8Nm/A, 4T = 1.07Nm/A, 5T = 1.34Nm/A, 6T = 1.59Nm/A
Lamination size: 0.35mm
Turn count (T): 3T-6T
RPM per volt: 3T = 11.9 Kv, 4T = 8.9 Kv, 5T = 7.15 Kv, 6T = 6.0 Kv
Stator/Magnets: 45mm
Max Efficiency: 90% Peak
Weight: 20.6lbs
Dropout spacing: 142mm (Standard) or 170mm (Fat Bike Version), or custom is possible.

Idea been beaten to death in this topic
https://endless-sphere.com/forums/viewtopic.php?f=2&t=64907&p=1104421&hilit=myth#p1104421

All from the same thread topic, different then the thread above, same topic.....
https://endless-sphere.com/forums/viewtopic.php?f=2&t=75059&p=1135555&hilit=myth#p1134974
https://endless-sphere.com/forums/viewtopic.php?f=2&t=75059&p=1135555&hilit=myth#p1135370
https://endless-sphere.com/forums/viewtopic.php?f=2&t=75059&p=1135555&hilit=myth#p1135032

I will see what I can come up with from Justin. If I remember he metions something about this, in a thread and a vid. Its been nagging me thinking about where I saw this whenever this kind of subject comes up.

https://endless-sphere.com/forums/viewtopic.php?f=2&t=64907&p=992145&hilit=myth#p992145
https://endless-sphere.com/forums/viewtopic.php?f=2&t=64907&p=984783&hilit=myth#p984783

When you compare two motors that do have the same fill, like the slower 7x9 with the faster 9x7, you still get a difference in the torque output off the line, because the faster winding motor needs more current to produce the same torque, and outside the motor, more current means more losses in the motor controller and motor phase leads (but not the battery leads, as the battery current stays the same).

 

[Jacq]

RPM /Volt: 3T = 11.9 Kv, 4T = 8.9 Kv, 5T = 7.15 Kv, 6T = 6.0 Kv
Yes I will ask the moderator, thanks

 

[Jacq]

Flat road, no traffics, not best asphalt , no hills 9 miles one way.

 

[dogman dan]

He's not in the USA.. Might be best if his bike does not do 70kph. He's going to be a tad past 250w already...

Not sure how you get that motor to pull max amps for 10 min,, he'll be in a lower amps cruising mode in about 50 meters. He won't be able to overheat it even if he exceeds the max amps with the controller, because the motor simply will not demand it. Well, he could max it if he put the wheel against a building, and rolled back the throttle. But on the road, he'll just zip up to full speed too fast to make much heat. Once cruising,, going slower, he'll be pulling amps well within the ride to infinity range.

Yeah,, I'm the dope that loves low speed winds. But,,, in a specific use, where speed is not the goal, they can make sense.

3t wind though, if he was running a 20" bike tire. I think hes planning on 19" moped tire, a bigger wheel.

 

[Jacq]

''He's not in the USA'' yes, but Ireland is not Police country to. Allways I can use PAS just in case. I do not have to use 70 km/h but I will be a nice option.
The adaptto controller is 65 Amps, so making a battery of 20s11p , 18650 3.5 amp 10 Amp hi discharge ?

 

[nutnspecial]

Okay, so you'll be @ about 38mph on a 25" diameter tire. Unloaded!!!
At nominal cell levels (72v* 6kv* 6.54' [strike]dia[/strike]<circ>) that should be 32mph.
You should see 35mph round trip for the commute you describe . . . and alot of torque for playing!!

I'm gonna go out on a limb and say that ~5kw 'geared' for 32-35mph is gonna be alot of fun 8)

So the cells are 3.5ah rated @ 10a? That's about 3c, and it's usually best to not exceed 1/2 of that for continuous draws. A 38ah pack should do 60a or 65a pretty comfortably.

 

[Jacq]

Thanks

 

[LockH]

 

[markz]

20s11p , 18650 3.5 amp 10 Amp hi discharge ?

That would be 110A at your disposal. 11P x 10A. Nutspecial is right though, you want to discharge at a lower level to expand the lifespan of your cells.

The MXUS motor is a good motor choice. It has a very desirable price point. Sheds heat really well. For a commuter it might be too much motor, if speed is not king.

Remember Jacq is a heavy dude, and getting a 3T with a 17" or 19" wheel is desirable.
Just play around with the motor simulator. Comparing 3T to 6T.

 

[Jacq]

11p x 3,5 amp nominal = 38,5 amp, so I am short 26.5 amps. The 65 amp controller has to get 65 amps or not ? 10 A high discharge battery is for covering of the different in peak in my understading. That set up = long life battery, best to not exceed 1/2 . So 65 Ams/ 5 Amps =13 p , Am I right? Is there any option to give less Amps to the controller ?

 

[nutnspecial]

That's a nice diagram/table! I do wonder if the guys running 3t and 4t would concur?

Anyway, 65a will make for great acceleration, but I don't think your build and conditions will draw that at full throttle. Maybe 1/2 to 2/3 at most?
Any programable controller can be set for battery amps, and afaik also phase amps for motor, among other this. ALOT of other things on an adapto from what I hear.
And yes, 13p would be more happy than 11p for 65a, but whether 2p difference would make-or-brake depends on how often you're using that heavy draw.


Ps, Lockh that's a nice table too. Uh, but fatality probability? You mean it can come down from 100% for us? :wink: :lol:

 

[Jacq]

Be honest I am thinking about 4T.