OK, so news like this is always deserving of a post, so I wanted to get this up tonight. We made a test run 7pm tonight to test that the hydrogen was being regulated to the correct pressure, and now the cells are running very reliably at high current.
A special thanks to Ballard: Using their very valuable feedback, and newly acquired data from our bench test setup, we were able to correctly calibrate the hydrogen supply to the fuel cells. Horray for teamwork!
After making the changes, at 10pm tonight we pulled roughly 520kW (700 horsepower) from the fuel cell stacks for about 1 second after ramping and holding 400kW, then 450kW without any problems, for a total test length of 50 seconds. Everything was running great, but we ran out of hydrogen fuel, and we can't run without that. Needless to say, the resistors do heat up a bit: