Low ESR Capacitor for ESC, does this apply to 3DR Solo ?

[ken_chuang]

Adding low ESR Capacitor to ESCs is widely discussed in custom racing mini-quads. You can refer to these YouTube videos for info

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I am curious if this would apply to 3DR Solo ESCs as well, especially when I see a 220uf 25V, which looked like a Vishay 021 ASM Capacitor in the ESC. I am not sure if this capacitor is actually for the same purpose for noise filtering.

Would like to know if anyone in this forum had already tried changing or add a low ESR capacitor with a higher uf and volt value to 3DR Solo ESCs ? Thanks in advance.

 

[Pedals2Paddles]

It's unlikely that it will make a noticeable improvement in anything you can see or feel on a solo.

 

[fpvsteve]

Adding low ESR capacitors to the ESC input power lines is a common practice in high performance brushless motor setups to improve the stability of an ESC under high current peaks well beyond the specified current limits.
Eg in F5B racing, we “stretch” a 160Amps spec’ed ESC easily to 250 Amps peak loads.
Such methods may be relevant for drone racing as well, but certainly not for a Solo.

 

[RichWest]

Watched the above videos and a few more, crap I know nothing. One thing mentioned was reducing desyncing issues. Would ESR caps reduce desync to the motors?

I do understand there is a voltage issue and a work around gave us Solo as it is. When new ESC's are released I'll jump to the GC. I don't like change, but when I do...

 

[fpvsteve]

Watched the above videos and a few more, crap I know nothing. One thing mentioned was reducing desyncing issues. Would ESR caps reduce desync to the motors?

I do understand there is a voltage issue and a work around gave us Solo as it is. When new ESC's are released I'll jump to the GC. I don't like change, but when I do...

Rich,
At less than full throttle settings, the ESC pulses the current to the motor and consequently draws current from the battery in pulses. Wire however has inductance, and inductance resists the rapid change in current. Because of this, the supply voltage at the ESC wants to pulse up and down. The longer the wires OR the higher the motor current, the more inductance, and the higher and lower the supply voltage at the esc goes. The pulsing supply voltage can cause operational instability in the esc, and can damage components on the esc.

The function of the capacitor is to supply current when the supply voltage goes down and sink current when the supply voltage goes up smoothing out the voltage. The ESR limits the current the capacitor can source and sink, keeping it from doing its job.

Every brushless ESC comes with such capacitors attached. To add additional ones to the Solo ESCs won’t harm but won’t give you any benefits either.
The problem with the Solo ESCs comes from PWM signal level drops. See here:
https://3drpilots.com/threads/3dr-solo-escs-firmware-updates.11409/page-3#post-120697

 

[RichWest]

I appreciate you answering and explaining it out. Was hoping there was a magic bullet... It makes sense now, information gathered prior to this thread. Again I appreciate your reply.