Thanks! I may call on you for these.
In the meantime I have established the board is OK, and that the GG1 won't pull squat with only one motor driving one truck, and the other truck totally free wheeling. I have also established the Kohs pickups are quite a drag. And they are on both sides. Not a good design. I partially addressed that, and improved the run time.
I am currently pursuing two options
1) Go to more efficient motors (my original course). My goal is to get below 1 Amp, where I know it will run for a long time.
2) Put a second PS 3 board to drive the second motor and run the whole thing as a Lash Up. Per Pat's suggestion. Space is a challenge, but we'll see
Your fan gives me a third.
Incidentally, I considered dunking the board in a thick copper mini bath tube of fluorinert.
Would have solved the problem. But sealing against leaks would have been a challenge.