ok im getting started on an electric go kart and im pretty stoked. i just have some things i need to clear up on. i am going to run 48 volts on a 36 volt golf cart motor, which is what the golf cart was running on before i took it apart. i now have the batteries, motor and old controller (not solid state) out of the golf cart and ready to be made into a go kart. i am unclear exactly what controller i need for the best performance.
what i have:
36 volt series electric motor. cant find any info on it. all i know is that its rated around 2000 watts, 50 amps.
6 eight-volt batteries that are like 7 years old but still hold some charge, cant afford new ones.
old style speed control i wont need.
ebay has one controller that i think would work for my kart. it is rated at 48-60 volts with 60-100 max amps, and is made for less than 2000 watt motors. i'm unsure how it would work using it for a 36 volt motor with 48 volts. if the controller says 2000 watts or lower, does that mean just the motor must be rated 2000 watts or lower, or the actual power going to the motor (which will be higher with 48 volts) from the batteries? the amp rating on the controller seems high (up to 100) and its meant for 48-60 volts, so it seems like it would be good. but im just not sure if the controller would limit the watts to the motor or be overpowered and burn out.
im just confusing myself the more i think about it..its probably a lot more straightfoward, i just dont know how controllers and motors work with different power ratings
oh heres the controller: http://cgi.ebay.com/NEW-48-60-Volt-Controller-Model-ZY-KK70-/330424799222?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item4ceeda4ff6
not sure if it would give too much power to my motor or if its to weak.
you could probably get away with overvolting that motor to 48v, but I reckon those heavy old batteries wont give you best performance.
I think buying 4 (5ahr 22.2v) lipo packs and making a 2s2p pack out of them will give u a fantastic 44v 10ahr ride as the weight component will be so much less. Those packs are cheap on ebay (around $40 each) and at 30c can deliver the peak amps you need.
The old batts you have will ultimately give you poor performance
ok i think i might replace the batteries but what do you mean by 2s2p pack? do mean just paralell?
if i could get a link to those batteries thatd be great. and i have a series motor so will paralel still work?
im still unsure which controller i need (max amps) to go with my motor. i want it to be fast but not to much money.
He's saying that if you use just a pair of the 22v 10a batteries you can get 44v at 10a, but if you use a second pair you create series/paralell (2s2p) and get 20a for your 44v.
WHo dares, WINS!!!!
hey, i am making a go kart with similar specs. I was very confused about how the controller would work? since the battery is 48V will it always supply 48V to the motor? wont this damage the motor? is there some way to program the controller to give 48V to the motor when the kart starts(overvolting to overcome the initial torque requirements) and then limit the voltage to 36V?
So the short answer is NO.
Extremegokart and gokartfreak are the main participants of this article in building go carts and keep us informed of progress. If either of you guys use a controller just make sure of the working parameters of unit. This way you can use it for another project down the road. In other words you can use a 500 amp controller to use for go-cart and or a light bulb or a big Volts Wagon!!! As in Dune buggy. I bought a kit and it is still in the box to build a go cart. I have lots of controllers and a small assortment of Lithium battery packs left over from a motor cycle project and I too am thinking of build a play toy using my new Harbor Freight MIG welder. I am going to make battery hold down a quick removal since it will be stores most of the time.
Just a quick note to see how a PWM device works. Take a contactor like a Curtis and wire it up to a battery. Let us try it with a 12 volt coil? Hold the bare wires in your hand and turn contactor on and off fast. It goes up and down real fast and you feel a tingle in your hands and fingers. That is wasted electrons. Now hook a diode across contactor coil with cathode properly placed on coil on positive side. Now do the same thing turn contactor on and off real fast holding bare wires in make and break format. Contactor stays energized and pulled in longer. No electricity in hands and fingers anymore. That is sort of the basic operation of PWM controller. PS don't do it if your ticker is weak.