Originally Posted by
segmentfault
Thank you for your all your replies, and it's basically pretty much what I expected. I'm going to try to calculate average power draw as half of the total wattage for the motor, then go from there. I'll post my results and see if we can come up with something to at least ballpark the differences between motors.
What happens when you put a 6s in a 2200kv motor as opposed to a 4s in a 2200kv motor? Obviously you will go quicker, but if you were to decrease the size of the pinion and motor timings and actually control the added acceleration and speed by practice, theoretically because of ohms law (w = v * a,) wouldn't you have longer runtimes?
6s, 22.2v * 5a (c value for a point of calculation) = 111 value
4s, 14.8v * 5a (c value for a point of calculation) = 74 value
thats a 50% increase in total power of the battery. With a 50% increase, and considering you can keep wheel spin and acceleration near the same with the 6s as with the 4s, shouldn't you also increase your run time by 50% with no other factors considered?
Obviously the weight of the battery is heavier, and there are a few other values to consider such as voltage drops across the wires, electronics, etc.
Anyone have experience with this situation?
seg
No, you will probably get less run time if the pack energy is consistent (4s 5000 = 6s 3300). A 2200 motor on 6s is 48k RPMs which is going to generate a lot of heat and wasted energy. Even if you gear down to the speed equivalent to a 4s on 2200, the energy used to spin at 48k rpm is negates the benefits of the higher voltage.
Every motor has it optimal efficient rpm range even though most of the motors are good to 60,000 rpms. IMHO most of these setups run most efficient when the motor rpm is between 28-32k rpm. Once you start going above and below you generally start seeing higher amp draws even if you are using higher voltage. this is why mating the right kv motor with voltage is critical.