Originally Posted by zaidq8

Hey there, this is my first post, I’m not new to RC world but I was busy in other things for the past 10 years, a lot of things has changed !

I’m an electrical engineer and I’ll try to apply my knowledge here a bit, btw the brushless motor is simply an AC 3 phase induction motor

Anyway, I just bought a brushless 1/16 car with a 3s battery and a brushless motor which I changed to Novak mangooso 9000kv motor .. ( I know !! ;P )

In my first run on the new motor, I found that the battery was cooked and realized that current capacity wasn’t enough so I search the web for a way to select the Lipo. I found that a lot of posts talk about calculating the current capacity of the battery only which is rubbish ! all of us know that. At the end they select the biggest capacity and try to be on the safe side

so I made some studying and here is what I think:

Simply, current = V (voltage of the battery) / R (resistance of motor and ESC which is constant)

So the higher voltage you put will lead to a higher current drawn by the system and more power is consumed (higher speed).

If you have two 3s battery with a 20A current capacity each and you connect them in series then this will not increase the current capacity, it will remain 20 A. I’ll explain more if you want

6s will only double your current demand because you doubled the voltage.

Bottom line, brushless system manufacturers should provide the current demand data (for the motor with ESC) on the battery side for different voltage levels (2s, 3s, 4s … ), after that selecting a Lipo will be a piece of cake