# Motor output limiting

Can you configure your motor output limit on betaflight or DJI goggles?

I know you can do it through the fatshark goggles, but I do not have parts to build a drone, so I am asking before I get 2700 RPM/V Kv motors for a 5 inch.

Formula:

LIMIT = desired Kv / real Kv * 100%

Example of the formula being used:

LIMIT = 1800 RPM/V / 2700 RPM/V * 100% = 67%

• can you elaborate? what do you mean by motor output limit? do you mean rampup power? maximum throttle? what exactly are you looking for? – Bastian Springer Jun 6 '20 at 16:09
• Formula: LIMIT = desired KV / real KV * 100. Example: 67% = 1800 / 2700 * 100 – DroneDome Jun 6 '20 at 16:22
• I don't see how that answers my question đź¤” – Bastian Springer Jun 6 '20 at 16:30
• @BastianSpringer, I'm basically trying to lower the KV of my quad motors so I can use a 6s battery rather than a 4s battery. I do not know if lowering the kv of motors is dealing with rampup power or maximum throttle so i cannot answer your question. My question is, if it's possible to limit the KV through betaflight or/and dji goggles since i do not have a built drone to find out. I'm assuming you can through betaflight since you can do it through fatshark goggles, i just want confirmation. I hope that clarifies a bit. – DroneDome Jun 6 '20 at 16:41
• Kv = motor velocity constant (AKA back EMF constant). Unit: revolutions per minute (RPM) per volt. e.g. 5,700 RPM/V. – Peter Mortensen Jun 7 '20 at 16:25

I don't think throttle limit is the way to go, it will still allow the motors to spin too fast for a 6S setup.

You can set motor_output_limit in the CLI and it is linked to your current profile. If you want to fly both 6S and 4S with the same quad you can use auto_profile_cell_count to switch automatically between profiles

• Thank you for your response. I shall give that a try – DroneDome Jun 18 '20 at 2:40

I don't think that you can edit the throttle limit directly in the goggles, but you can change rateprofile in the betaflight OSD.

So what you can do is to set up a few different (up to six) rateprofiles in betaflight, and then change between those in the OSD. It won't be as granular as changing the limit directly, but it should be enough if you just want to change between a few different values.

To make it even faster to switch between the different limits, you can even assign a switch to do it.

Here is a guide on how it is done.