So who here knows a lot about electronics?

[trax de max]

@trax de max what's the particular reason for not limiting the in-rush current on a MMM? I wonder if this is related to its 'cell' detection circuitry?

I'm not sue if it's on castle's site or a site on how how to make them which said that it it hasn't got to be used with the MMM line. But never mentioned any of the other esc's, It also has the spark you see is a good thing, and that if you don't see no spark it is possible that the caps are bad.