Speed control capacitors.

[Sammus]

I also heard someone say (or saw someone write lol) it had to do with poor quality batteries due to their voltage drop under load. Like for a split second when it starts the voltage drops substantially then shoots back up once its moving, and somehow that translates into ripple (what I was reading was actually talking about ripple voltage...not sure if they amount to anything similar...)

[Taylor]

ok thanks guys, on another forum, they had something posted about it and that most of the time they are used for bigger motors for brushless, and they have about 8-5 of them on there.