allthough being a newbie to electric drives, I did study EE but am not best informed on BLDC. My collegue and I have the honor to build a car prototype which drives only with 6-10 km/h and we have a 24 V LiIon battery (7S8P). Now I have the feeling that our little motor, which is a 15 W, 24V motor rated for the 8S7P will juts not have enough power. So i think of changing the motor but have the difficulty finding one, which is rated for 7S8P. (24V).
So my question is: How does the battery voltage relate to the rated motor voltage? If e.g. I would choose a great Hacker motor which is only rated for 8.4 V, can I use it with my 24V battery on the vesc and what is the consequence? Trivially, i would say that the max available power of the motor will only be 1/3 of the one given at the datasheet, because I limit the current in vesc tool but the voltage is only 1/3. But is this true? And why do so many good motors have no real voltage rating? (https://www.hacker-motor-shop.com/Elektromotoren/Hacker-Innenlaeufer/Hac...)
What if I use a higher voltage battery, than the motor likes?
As a follow-up question I would also ask: what does this mean in theory? We use FOC controlling, which also generates some kind of pwm signal for the motor. Is the voltage "height" of the pwm signal equal to the battery voltage? so if the battery delivers 24V, and the battery is only rated for 8.4V, than will this fry the motor due to overvoltage?
I am totally confused, althouth I do understand the relation between amps from battery and to motor (basically keeping the input/output power equal).
Thank you very much for your help!