John in CR
100 TW
Ok I'm spoiled with more performance than I have the balls to use, but there are aspects that come with it that I refuse to give up, such as still having scary acceleration at any point in the speed range I typically ride. The unavoidable shape of the power and torque curves means running a voltage high enough to make top speed faster than you use, but is there a cost beyond what comes with using the extra performance?
There seems to be a cost in terms of controller efficiency, since riding at high power but partial duty has always made my controllers run hotter than they do running similar performance at lower voltage. It doesn't seem to make a difference to the motors I use, because I don't see them make more heat unless I up the current or increase the load for more time at similar current. Is this my imagination or is it real?
The distinction is important as I build some long-range ebikes with big battery packs of 45-60ah or more. I don't have a problem running more capable controllers than are necessary to keep their resistance lower and reduce losses, but there's nothing I can do about the motor(s) and I much prefer having the extra performance on tap. Plus, in the mountains a small difference in heat generated can add up quickly.
It boils down to one question. For the same torque and rpm, does it make a difference in the motor at what duty cycle the controller is running, or is the difference insignificant? I think the answer is no, though it may depend somewhat on the motor. Does it depend on controller type too?
There seems to be a cost in terms of controller efficiency, since riding at high power but partial duty has always made my controllers run hotter than they do running similar performance at lower voltage. It doesn't seem to make a difference to the motors I use, because I don't see them make more heat unless I up the current or increase the load for more time at similar current. Is this my imagination or is it real?
The distinction is important as I build some long-range ebikes with big battery packs of 45-60ah or more. I don't have a problem running more capable controllers than are necessary to keep their resistance lower and reduce losses, but there's nothing I can do about the motor(s) and I much prefer having the extra performance on tap. Plus, in the mountains a small difference in heat generated can add up quickly.
It boils down to one question. For the same torque and rpm, does it make a difference in the motor at what duty cycle the controller is running, or is the difference insignificant? I think the answer is no, though it may depend somewhat on the motor. Does it depend on controller type too?