New Build component compatability

[higgypoo]

Hey Folks. Finished up my go kart...ended up with some pretty big issues with the motor/controller. I had it working, then it wouldn't (on repeat...many...many times) When it was moving, it was working great! So, I decided to part it out and start from scratch on a simpler project. Going to be doing a Big boy scooter.
So I have questions... I keep getting mixed answers about compatibility between motors and controllers and batteries. So here is what I'm thinking...Let me know if you see anything that won't work, or could work better.

Battery (owned already):
-72V LiFePo4
-40Ah
-80A continuous
-160A 5S peak
-onboard BMS

Controller (NOT owned): (is this too big? too small? I was leaning towards this or a 70A controller, but its hard to find 72V ones to take advantage of my battery)
-72V compatible
-80A
-max 200A
-rated for 3000-5000 watt
-Temp regulated

Motor (NOT owned):
-hub motor
-17" total tire height (big I know, meant for bike)
- 48-96V rated
-3000watt (I know this varies, but this is rated)

Since I've got a 72V battery with 80A continuous...should I be looking for a motor that is rated for at least (72 x 80) 5760Watt? What would happen if I ran a 3000 watt motor..would it burn up eventually or just get warm? I'm mostly stuck on the motor. Its actually pretty darn hard to find a motor over 3000watt that runs on an 80A controller. Most of them want 100+ . Also, what happens if I run a 10000watt motor? what would happen...just wouldn't reach full potential or would it wimp out or something?

Suggestions?...

 

[Functional Artist]

Here is an example of running a kart with too small of a motor (MY-1020 48V 1,000W)
("I'm givin; 'er all shes got, captain")

Now, I have the (ME0708) "little brother" to the (ME0709) motor on my Hell-raiser kart
...& it's BAD AZZ

This motor is capable of 72V 80A easily

Motenergy ME0709
Designed for 24-72 VDC battery operated equipment.
Capable of 300 amps peak and 125 amps continuous.
Totally open, fan cooled motor.
https://kellycontroller.com/shop/mars-0709/

...& a Kelly KDZ72400
Max operating range: 18V to 86V.
• Configurable battery voltage range, B+.
• Motor Current Limit, 1 minute: 400A.
• Motor Current Limit, continuous: 160A.
https://kellycontroller.com/shop/kd...te_pa_current=400a&attribute_regen=with+Regen

 

[higgypoo]

This motor is capable of 72V 80A easily

Motenergy ME0709
...& a Kelly KDZ72400

Thanks! But looking at these, I'm still not quite understanding something. My battery is rated for 80A continuous and 160 peak... so it wouldn't work with a controller like the one you linked...correct? That one needs 200? I know the motor will just take what its given from the controller, but as far as I've read, if the controller wants 200, it can fry the battery trying to get that amperage? Am I right on that? I'm mostly trying to avoid buying another battery since this one cost me 1k lol

 

[Functional Artist]

Thanks! But looking at these, I'm still not quite understanding something. My battery is rated for 80A continuous and 160 peak... so it wouldn't work with a controller like the one you linked...correct? That one needs 200? I know the motor will just take what its given from the controller, but as far as I've read, if the controller wants 200, it can fry the battery trying to get that amperage? Am I right on that? I'm mostly trying to avoid buying another battery since this one cost me 1k lol

IMO Key words are:
Capable
...& Current Limit

The motor is "capable" of handling up to 125A continuous (all day long)
...& 300A max

The "current limit" of the controller is 160A continuous (all day long)
...& 400A (for up to 1 min)

The kool thing about these "higher end" controllers, is that they are configurable.
...so, you can connect a programming cable, to a laptop
...& "go in" to set many of the parameters & customize it to your specific situation.

I haven't done this, much yet
...but, IIRC Epsilon Zero & Bmr4karts have both "gone in" & configured their controllers

* Hopefully they can "chime in" with some more info, about that, for you

 

[higgypoo]

The kool thing about these "higher end" controllers, is that they are configurable.
...so, you can connect a programming cable, to a laptop
...& "go in" to set many of the parameters & customize it to your specific situation.

I haven't done this, much yet
...but, IIRC Epsilon Zero & Bmr4karts have both "gone in" & configured their controllers

* Hopefully they can "chime in" with some more info, about that, for you

@EpsilonZero @Bmr4Karts If you guys have any experience lowering the continuous amp draw on a controller, I'd love to hear how easy/complicated it is.
@Functional Artist Yeah, I was kind of hoping that was the case to be able to program that part of the controller, Just can't seem to find much info about what parameters can actually be altered.

 

[Functional Artist]

FYI:
There's are (4) downloads available, about the controller, in the link in post #2

Just scroll all the way to the bottom to:
...Features
...Specifications
...& Downloads

Controller User Manual
User Configuration Program Set Up
Assembly Wiring Diagram
Assembly Wiring Diagram (with F-N-R function)

 

[EpsilonZero]

It is easy. The battery current limit setting has been available on all of the Kelly controllers I own. It is a percentage of the maximum available rated current. There are both desktop (Windows) and Android apps that can configure it. The Android app requires a Bluetooth accessory that is sold by Kelly.

 

[higgypoo]

This is good to know. I am going the sabvoton route since it looks like they have the same feature as the Kelly controllers for adjustability. Thanks for the insight guys.

 

[higgypoo]

@Functional Artist , I had great luck with the precharge circuit I made a while back using your videos (much appreciated).
I'm curious. Whats the rule of thumb you use to determine the Amp rating for the breaker you use? My battery is rated for 80a continuous, and 120 peak i believe.. what good would a breaker be if it was a 150a? Or should I keep it somewhere between 80 and 120? Thoughts? Thanks buddy!

 

[Functional Artist]

Kool! I'm glad it helped.

Usually, a fuse or circuit breaker is rated a little bit higher than the "load" it should/would be carrying.
...but, not too big (or it won't be sensitive enough to "break" when/if necessary)

Your very welcome

 

[higgypoo]

Usually, a fuse or circuit breaker is rated a little bit higher than the "load" it should/would be carrying.

Cool yeah, thats what I assumed. Thanks

So, I'm trying to do my homework, but comprehensive videos on wiring are almost impossible to find. ie; I haven't ever seen a video with someone adding in a precharge circuit. Are there other secret things I should be doing to my set up? like...what are shunts for? Do I need a 12v converter? these are just some of the terms I've heard, but can't find much on them.

 

[Functional Artist]

Cool yeah, thats what I assumed. Thanks

So, I'm trying to do my homework, but comprehensive videos on wiring are almost impossible to find. ie; I haven't ever seen a video with someone adding in a precharge circuit. Are there other secret things I should be doing to my set up? like...what are shunts for? Do I need a 12v converter? these are just some of the terms I've heard, but can't find much on them.

A shunt is a measuring device, that sends info to a power meter.

A 12V convertor (AKA DC to DC convertor) is a component that takes (some) power from the battery pack (be it 36V or 48V or whatever)
...& converts it to 12V so that, you can power 12V accessories/stuff like lights & radio etc.

If you haven't already, check out & read thru the build thread on my mini-Slingshot

https://www.diygokarts.com/community/threads/slingshot.45461/