I currently have a pretty weak 6s LiPo battery powering dual 5055 270kv motors and I live in a very hilly area. I want to upgrade my LiPos soon to a better Li-On pack and found the 10s5p Li-On pack from diyeboards. This is a very good price (I think) but the problem I think for me would be is that it only outputs 50a. so would 25a per motor be enough? I know 270kv is quite high so I want to change the 3:1 gearing ratio to 5:1 when I upgrade the battery.
So I’m basically asking would 25a per motor be enough and with a 5:1 gearing ration should I be able to get up steep hills?
Depends largely on your weight. Also depends on your definition of steep. Also depends on what your definition of “go up” is. You might get there, but not the fastest.
Some of it will just be trial and error. I always side on the side of more amps. But another big factor is the motor. I can’t speak as much on whether this will work or not, since I’m not a belt guy. If I were talking about hub motors, I would say 25 amp per motor is not that great at 10s. But belts can get a bit better efficiency, so you might be able to squeeze a bit more out of them.
Thanks for the reply!
I only like to go at 25km/h not even. not sure how to describe the steepness, Im not that heavy im only 16.I think I will probably just have to wing it and hope for the best I would like to get higher amp battery pack but unfortunately diyeboards dont sell anything high
I ran some test with an in-line watt meter on a dual drive and my weight being apx 185 lbs going up a hill that was apx 10% grade
Using 12s Opto Car Esc’s and Carvon V2 direct drive motors with 90mm wheels
Both tests where at apx same speed
12s - 18a total from battery at half throttle
6s - 36a total from battery at full throttle
That should put 10s at apx 27a total
But as previously mentioned, there are many variables.
@Orin635 here is a chart predicting the performance you will get with 25a battery current limit and 80a motor current limit per motor (83mm tire, 3:1 gear reduction, 2 motors, 270kv, 22.8v battery)… top speed looks to be about 19mph (red line, bottom left chart - thrust pounds minus wind drag force) and peak vehicle thrust is roughly 90lbs (yellow line, bottom left chart - vehicle thrust pounds 2 motors):
right, notice how the back emf voltage produced by the spinning magnets on the rotors (which opposes the battery voltage - red line top left chart - back emf voltage) increases with speed and surpasses the maximum pwm effective voltage of your battery/controller right below roughly ~20mph (yellow line, top left chart - effective pwm voltage).