Slightly off topic, but I know hydrogen fuel cells (for automotive applications) car run around 350 amps at almost 200 volts, that is "short term" levels... aka can hold it there for 10 minutes without damage, but the fuel cell gets pretty hot if held there much longer. At "continuous" levels, the ones I saw were stable around 250V and 250A. The only issues currently are reliability and cost (uses lots of platinum) as well as storing enough hydrogen onboard (safely) to go more then 200 miles.

/Ending non RC conversations now/