My Senior Project Plans

[hbcolf]

Hey everybody!!

So I am a senior in hs, that means I have to do a Senior Culminating project . I am interested in making an electric go kart that can maybe be charged by a solar panel to cement the whole green energy thing, but that comes in later if I feel so inclined.

So I have several questions about how to select the proper motor/battery/controller set up. I have an idea of what kind of motor I would like to purchase, either a truck starter motor or maybe a treadmill motor depending on cost. So what kind of battery set up would I need? If the motor is 24v would I need to get two 12v batteries to make it go? or could I go with one battery?
And I understand what a controller does, I'm just slightly confused with the voltage ratings and the wattage ratings.

I think that is all for now, I'll be sure to post an update to here if I move forward or have any more questions.

Thanks HB

 

[landuse]

Welcome to the forum. First off, read all the sticky posts in the electric section. There is some great info there

 

[itsid]

well,
let's outline some things for your convenience

Solar panels are nice when mounted to a kart-port to charge the kart,
maybe with some sort of energy storage (can be about anything)
easiest: a second battery pack to just swap the packs and move on

They are not too good mounted to a kart, first they add weight without the capability to make noteworthy use of the energy they provide,
and second they're expensive, in case of a mishap you risk loosing a panel.

So let's stick with the kart.
The most important thing is to be as efficient as possible
that means, keep the kart as lightweight as possible,
steer away from suspension two seaters and whatnot.
Then choose the smallest motor that'll serve your needs
A smaller motor will require less batteries, and thus will add less weight;
it's likely smaller and lighter than a higher powered motor too

because of efficiency, do not use a car or truck starter,
and I wouldn't even suggest using a treadmill motor either.
if you have one laying around, that's fine, if you have to buy one..
buy a motor that's made to run a vehicle.
It's very likely that you end up with a much better efficiency,
and spend less money in the end.

And as a benefit, for those motors there's almost always a perfectly matching controller available, most even fairly small and cheap as well.

take a my1020 1000W motor and its YC31 companion controller for example...
that's ~100 for the motor and ~30 for the controller, and all you need to add is batteries and throttle (+some wires) to power a kart.

to get the same power from a truck starter you'd need to find a starter with at least 2500W and a controller with at least 120 Amps (more likely to be in the $100 range alone) so even if you find a starter for just 30 bucks you gain nothing but loose efficency and will need to make some serious modifications to make the starter work,
and then, shortly after that the motor will fail since it's not made to run for more than maybe 10-20secs at a time in a 15min period. (they overheat really fast)

A treadmill motor like dcastillo has for example requires 90V, that's a huge amount of batteries,
and while it's very possible to run it at a much lower voltage, it'll provide less power with less voltage of course, and you might end up somewhere around the same 1000W of mechanical power but with a lot more weight on the kart.

Again, that's perfectly fine, but not exactly efficient

If you already read my thread about how to determine what motor you need,
you might have an idea by now what power rating you need.
If you don't let us know what kart you have in mind (DIY, yard kart, fun kart, race kart, dirt kart.....) and we'll be able to narrow it down.

And yes, if a motor wants a certain voltage, it works best at exactly that voltage,
sometimes it doesn't work at a lower voltage at all.

'sid