MMM V3 on 8s lipo?

[BrianG]

There is a little device on the ESC that helps limit the back-EMF voltage (over 28v) from getting back to the batteries. Running battery voltage above that will blow this device in short order thereby removing its benefit.

Then, the FET ratings are probably only good for 30-35v, not to mention the caps and any other voltage-sensitive devices on there. So, running at more than 6s will be running really close to component limits, even taking into account the extra "headroom" manufacturers factor in for safety.

Lastly; it may run at higher voltage, but you are almost certainly reducing the lifespan...