Thanks for the update deveauzt. I've spoken with the designer of the board and sent him a description and pictures of what happened so that the manufacturer is aware of it. When he saw my pictures he said..."It's pretty obvious from the second photo that battery power was shorted. That Pch FET with the crater in it is the 110A high curret switching FET that allows a normal, cheap power switch to switch the high currents the controller can handle. Looking at the first photo I would say that it's a good chance the Switchmode regulator also got fried. In that case the 5V regulator might be trying to step 11.1V down to 5V when normally it would be reducing 6.2V to 5V. (Just a guess). That might explain the wisp of smoke since the input capacitors on the 5V regulator are only rated for 10V. That might explain the wisp of smoke since the input capacitors on the 5V regulator are only rated for 10V."
That may help you in your understanding of the board. In my case, I chucked the first one as a casualty of war, and got a new one. I put it on my own standoffs. It has worked perfectly ever since. I like the board. However, I do wish it had more available digital pins to add sensors to, etc. You can use the so-called servo pins as general I/O pins, but I still need more.
Follow-up: I hooked the T'Rex up on a basic RC transmitter/receiver. It sort of worked for a little bit on the bench. The wheels turned in response to throttle movement, etc., but the slightest bit of movement caused little bits of smoke to come up. Then it got worse. Now when I give it throttle, the whole board resets itself. When I checked the back of the T'Rex board, the large black component labeled "110P04-05" looks like it has black marks around it and it's cracked. It clearly has suffered damage, probably overheating damage. I don't see any other visually obvious problems on the back of the board.
Thank you, Toni. That's what I needed to know.
I'm hoping to use this shield on an Arduino Mega 2660 R3. The shield's product page mentions "any digital pin on the Arduino (D2 and D3 default)". How does one accomplish changing the default pins? In particular, how do I change it to use D16 and D17 on the Arduino Mega? Perhaps that's not possible, since those pins are completely off the shield. Or perhaps I could run a jumper over to those pins. But I need to make sure D2 and D3 are not interfered with (they are being used by something else). I see the "3" and "2" solder pads by TX and RX, but I'm not sure how to utilize those or if those are related to my goal.