Are you sure the brakes on the ESC are completely disabled? No drag brake, brakes at 0%?

I highly doubt it....

This scientific article by a MGM Ing. explain everything...
http://mgm-compro.com/pdf/en-motor-braking-050409-g.pdf

I love this. I don't know how many arguments I've seen at that "other place", but the above really drives home what many more technically inclined people have been saying.

It seems to me that point A is really talking about the Zippy vs any-other-battery debate. High C rates mean little. Resistance is what really matters.

Point B makes simple sense. We all know that brake voltages can be substantially higher than the battery, so if someone is using batteries to the max ESC spec, it's only natural things can go wrong during braking. This is exactly why I NEVER run max spec voltages on ANY ESC. And between you and I, think this is why some people have been blowing MMM ESCs. Gearing a relatively heavy vehicle for stupid speeds on 6s, and then braking fast makes me shudder. Just imagine the kinetic enerfy contained in a 10lb+ vehicle traveling at 60mph+ and trying to stop on a dime.

Point C is basically talking about using some kind of TVS device to shunt overvoltages to a safe level. The MMM uses this, but like any electronic device, it does have limits on what it can absorb. I was rather surprised to see such high braking currents though; I expected values around 20A. And since those current spikes are so short and so large, it makes sense that you don't see much runtime increase; the battery simply cannot charge that fast. Maybe someday we'll see battery charge rates in the 30C range, but certainly not today.

Point D. Well, that is just asking too much of users IMO. When I'm running full tilt and then a curb happens to "jump in the way", the last thing on my mind is whether the ESC will handle the voltage/current spike if I brake hard. It's just instinct (for me anyway) to jam on the brake. :smile:

I would add an "E Point"

e) use mechanical brake if you can!

I'm a little confused regarding the comparison between the Kokams and the "not very quality" lipo. These are the values during braking:

---battery-------battery mΩ------voltage rise----peak amps
Kokam--------------80---------------12.5-------------140
low quality---------170--------------17.5--------------80

It seems to me that using a ESC that is spec'd to more voltage than your batteries should fix the "voltage rise" problem. The other issue is the high braking currents. The data suggests that a battery with higher internal resistance will produce less amps and be easier on the ESC. This goes against what else I've learned which is that you should always aim for the lowest battery resistance possible. What am I missing? To me, the safest solution seems to be an over-spec's ESC and high resistance batteries.

Voltage is more likely to burn something out than current is...

Usually, too-high voltage basically "punches" through whatever insulating material there is, which in turn generates high current. At the end of the day, it matters little if the ESC is a pile of ash.

So the MMM is for 6cells right that to me means you should use 4cells to be real safe 5cells max and always at least 35c right or wrong. And nothing but 6.5 connectors or larger. And gear for say 45MPH max.

The MMM is perfectly fine on 6s, I've abused mine on 6s and it handled it well. It's the really hard braking that kills them, I have my brakes down at 30% and I try to take it easy on the brakes. I killed my first one with really hard braking on 4s, my 2nd one has been rock solid for ~50 hours of use so far (about 1 hour of use on 6s and there's nothing left of my tires).

Maybe MGM forgot that the MOSFET can take a little over voltage just fine and I'm sure most companies that makes a 6S capable ESC uses 30V MOSFETs. What they need to do is work on a esier way to set up their ESCs :lol:.