Battery for "6374 170KV RC Brushless Motor 2800W 36V" for a Beach Tennis Ball Launcher

Other Hardware Motors, Mechanics, Power and CNC
1

Hi everyone,
I’m working on a project to build a beach tennis ball launcher and plan to use two 6374 170KV RC Brushless Motors (2800W, 24/36V) for propulsion. While I’m familiar with basic electronics, I’ve run into some doubts regarding the battery requirements for these motors.

  • System Voltage: 36V. Let’s assume the motors will operate at approximately 50% power.

At 50% power, each motor would consume around 1400W. Using the formula ( I = P / V ):

  • Current per motor: ( 1400W / 36V ≈ 38.89A ).
  • Total current for two motors: ( 38.89A × 2 ≈ 77.78A ).

Without considering other possible components I’d like to add, this is a huge amount of current for the batteries I’ve seen so far. Usually, they don’t provide this level of discharge. How could I run this machine for about 1 hour? I’d likely need a high-capacity battery to avoid rapid depletion and overheating.

My Doubts:

  1. Battery Size and Practicality:
    It seems like these motors require a huge battery capacity for consistent use, especially at high power. Yet, these motors are commonly used in electric skateboards and scooters, which don’t seem to use gigantic batteries. How are they managing this?

  2. Battery Recommendation:
    What type of battery should I use for this application?

  3. Scooters and Skateboards:
    If these motors work well in personal electric vehicles, what’s the trick to balance power consumption and battery capacity? Do they limit the motors’ power or use higher-voltage systems?

I’d greatly appreciate any insights or advice, especially from those experienced with e-skateboards, scooters, or similar motor setups. Thanks in advance!

2

Surely you have seen automotive lead-acid 12V batteries. Three in series provide 36V and would have no trouble supplying 80-100 Amperes.

The launcher presumably draws power for just a couple of seconds, while one ball is launched. What leads you to believe that 2800 W motors are required?

1 Like
3

Have you seen the launchers with flywheels?

4

I'm confused. Or is the 170KV a model and not a voltage?

5

“Kv” refers to the constant velocity of a motor (not to be confused with “kV,” the abbreviation for kilovolt). It is measured by the number of revolutions per minute (rpm) that a motor turns when 1V (one volt) is applied with no load attached to that motor.

1 Like
6

Why that assumption?
It may be a good idea to determine the power required to launch a ball and use that in your calculations for determining maximum current.
If they are not launching a ball it may only be 5%

7

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.