Newbie needs help for a go-kart project

Hello guys!

First and foremost, you have an awesome community here, been following you for some time now and now I finally have something to post.

Secondly, you'll have to excuse my lack of proper/correct terminology or knowledge of this topic, I’ve haven't been a part of this field long enough, nor do I have experience, to completely understand everything, in general, I do when it comes to your basic stuff, but not so much in some particularities when it comes to correlation of certain components between each other. Although I don't have complete knowledge in this area of expertise, I do have a very, very high level of enthusiasm and love towards it, which keeps me going and which enables me to pick up everything relatively quickly (partially also thanks to my IT background).

I got my hands on a Swiss Huttles go-kart (one of the rental models), which I’m going to completely strip down everything ICE related and convert into an EV.

I would really like to build it ground up using quality and well known/tested/trusted components/brands, so I don’t have to go back and redo something, or even worse if something goes wrong because of a "low quality" component.

Anyway, I have a few concerns which I would like to go through and if someone could help me out, It would be a great help!

1. I’m all good in terms of my motor choice (probably something from Lynch LEM200 series or something beefier from Motenergy, 72V system bottom line), but what are my options in terms of motor controllers being controlled in a particular manner, or to be more precise receiving “live inputs” and making split-second changes via additional MCU with set of different sensors?

For example, can I take an Alltrax DXE motor controller, or something else which is able to do this in terms of other motors controllers, hook it up to let’s say an Arduino, or other even more advanced MCU / SoC’s, which has different sensors hooked up to it and which is programmed to alter the motor controller configuration in real-time when sensor picks something up?

2. On that note, what’s a good quality option for such MCU / SoC which is also “open” / programmable enough to do something like that?

3. What should I look at in terms of communication channels (what’s flexible/open enough) in such a scenario, between the MCU to the motor controller that is? CAN, UART, something else?

4. What are my options in terms of good quality BMS (I’m planning to build my own 72V 21700 battery pack, I need around 300A in peak) which can communicate with the motor controller itself and be flexible in terms of how it works in relation, for example, to regeneration cut off and other advanced features, or is that controlled in a different way? Is that a thing or is / can that be controlled just from the BMS / charger side of things? I’ve found a lot of what seems to be a well reputable BMS, but I’m not sure which one could be “up to that”.

5. I want to avoid onboard charger solution (because, weight reduction, bro), so I’m trying to find a good quality “brick” converter charger (probably gonna go for an XLR connection), but I honestly can’t find anything expect Cycle Satiator or Luna Cycle. Is something like YZPOWER a good alternative or should I avoid that? If there isn’t anything worthy in terms of that, maybe I should stick with onboard solutions, something like Delta-Q or other alternatives?

6. My drive axle is currently belt driven, should I stick with it, or should I go for the chain, and could you explain why? Is this a pros and cons thing, or a certain situation requires a certain solution?

That should be it... For now!

Thanks!

Great to have you on board. Sounds like you will learn a lot (as did I). I am not totally familiar with Karts, mine is half way between a kart and a car. So I can't help with much other than to start a comparison of all the karts you can find and list all the components and their performance characteristics. Assuming the owners have been open and honest you should start to get ideas for your direction.

Your idea for the charger is a good one. But chargers are chargers. The only difference with an on board charger is that it is mounted on the vehicle. So don't mount it on the vehicle. I did the same thing on my car. You just need to buy some Anderson plugs to connect/disconnect the charge. I found a handy mount fitting for my Anderson plug so it isn't floating around inside my car.

Good luck on the project and keep us informed.

Welcome aboard.
I think your plan to do some programming is not so necessary unless you want. There are ready to go controllers which are programmed. Can be set through PC, Android, external screens on steering wheel/ handlebars, possibly toggle switches.
If it's light kart than maybe give a try qs mid drive 3kw. It's cheap, has 3800rpm, 6000+rpm with field weakening, 56Nm, ussually geared ~1:~5 with rear drive wheel on scooters / small motorycles, weights 11kg, can be belt or sprocket geared with sprocket or pulley already put by manufacture. It runs with Sabvoton 72150 (200A,450A unclocked version), or sabvoton 72200, Votol (150A,470A) and possibly other more expensive better controllers.
For this motor it is recommended to feed 150A battery and 470A phase and with these amps don't get hot in light ebikes so maybe supplied with slightly even more amps. So any controller around these specs or slightly more powerful might be worth to consider. Of course not all controller can spin this motor and some are better then other but my mentioned two are tested, cheap, and is ok to be used. If you want spend more go Nuclier (one of Soviets controller brand name) with their most powerful controller version, there is queue till you get it from Soviets, four months or so. Costs ~two two three times more than my mentioned two controllers, but people are happy about them, have nice external display for 80bucks. They have online store with all their products. Controllers are new, very light weight, powerful considering weight, can run lots of motors because can be programmed little bit more then some other controllers, have good field weakening (motor does not get hot but it is more concern regarding hub motors).
Look around www and/or this forum, people are happy about this little motor but mostly I saw it to go into motorcycles like Send 50cc, some 125cc frames, and some DIY frames. If it is geared propeller (correct front and correct rear sprocket/pulley and correct rear wheel size) than it pulls good to 100km/h. If geared not correctly it pulls over 140km/h but than does not have good torque. I'm trying to give you a picture what this motor is... I'm still talking about small ebikes (80kg-100kg plus rider).
QS is manufacturing few other but not on sale yet; more powerful mid drive motor so maybe you want to look into that if want more weight more power more amps.
You mentioned you built battery. So yes, you need at least 300pieces of 18650 sliglty lower these 2xxx to run this little motor, better 400pieces. If want go cheap way scavenge some electric golf / evolt / nissal leaf / bmw . They have good cells inside except Testa. Teslas 18650 cells are not high discharge therefore you need them a lot. If you use Teslas 18650 get at least 400pieces to be used with my mentioned power motor/controller and you will be still on the low number regarding cells. One needs always to keep his hand on battery to check if their are still within their temperature limits, not too hot. The only reason to use 18650 and bigger 2xxx because of better energy density and flexibility regarding final battery shape (triangular for ebikes, square, thick, thin, one brick, two bricks).
I was talking about 72v nominal 20S battery. There is no point to go lower anyways unless some older motors to be used.
That was my thoughts. Maybe for carts there are some better stuff to get and to find out.