Gupye said:
so would installing a 80a controller on a 3000w motor replacing with its stock 60a controller it would cause probelms or not from what your saying
There is no yes/no answer, so I'll restate what I said before, which is the best answer anyone can give you (given the little info we have from you so far):
If, based on the original post quoted at the bottom of this post, it's a 72v battery system, then an 80A controller would be 72 x 80 = 5760W.
Simplistically, not knowing any of the conditions under which you'll use it, or how you'll ride, etc., that's more than the motor is designed to handle continuously (assuming it's really a "3000w" motor, since too many places just say whatever they want about the stuff they sell, not what it really is, and we don't know what specific items you're looking at).
Even a 60A controller, running at 72v, is 4320W, which is still too high for continuous use, assuming an accurately rated motor.
To stay within continuous-maximum-usage limits, you'd need to use at most a 42A controller, for a 72v battery system.
If it's a different voltage, then you'd need to calculate power using that instead of 72.
But most systems are not used at their continuous limits, so it's often possible to use a much higher-output controller on a lesser-capable motor, as long as it is not used at that power level very long. For instance, on the right side of my SB Cruiser trike, I'm using a "500W" hubmotor at around four times that, for a few seconds each time I accelerate from a stop to 20MPH. It gets hot quickly doing this, but it only has to provide about 400-500w the rest of the time, or less, so it has time to cool off while cruising at 20mph before I have to do that again. By the time I'm at the end of the couple mile long ride, it's very hot, uncomfortable to touch on the outside, but not at damaging heat levels (is as much as 60C+ inside, though).
It probably couldn't do this for an extended period, but I rarely ride very far these days. If I did 20-mile rides in start-stop traffic, it might get hot enough to damage itself at some point. If I rode on hills, instead of flat streets, or on sand/gravel/etc that takes more motor power to handle, it would heat up more and faster, and probably wouldn't work very long.
Similarly, it gets hotter faster in summer when it's 105-120F out here (and much hotter at street level especially in traffic with no breeze so the hot pavement heats the air which heats the wheel and motor, etc), and doesnt' get as hot as quickly in winter when it's in the 60s at most during the day.
It also gets hotter faster when it's really windy outside, because the wind drags at the trike and slows it down, making the motor use more power to maintain speed.
So whether you can use a small motor on a big controller depends on your specific usage in your specific terrain, riding style, wind/weather, etc. If you are always running it at maximum, then you need a controller and motor matched in capabilities. (or a bigger controller that is programmed down to match the motor and won't exceed what the motor can handle) If you are only using maximum occasionally, you can use a bigger controller without worrying about it too much, depending on exactly how you really use it.
You can see how some of this works by using the simulator at http://ebikes.ca/tools/simulator.html and reading the whole page for instructions, then playing with different setups using settings that emulate your usage and terrain.
Gupye said:
I’m buying a 3000w base power e bike kit. I’m getting a 80A 26ah 72v battery. Should I get a 72v 80A controller to go with it or could I upgrade to a 100a 72v battery and a 72v 100A or would I run into problems. I’m worried that to much watts on a 3000w motor would effect it.can someone help me and tell me if I would run into any problems running a higher amp controller.