n72.75
Move slow and try not to break too much.
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This turns out not to have been the problem.... @indy91 actually added some code back in 2020 to prevent the divide by zero case that I caused.@Wedge313 I looked through the code, and I am fairly confident that the fix for the NaNs is just to guard against the potential of divide by zero cases (basically, we calculate the resistance of all the load attached to the cell and use that to calculate voltage drop and heat and a bunch of stuff, the input of that calculation is power draw...which can be zero...).
This is a bug I introduced a few years ago with my fuel cell update, but people don't fly 13 that often so we're just finding it now. It's an easy fix and I'll have an update out soon.
What is actually happening here is that because everything is on FC2 and FC 2 has just the right combination of load on it, its voltage and current draw are increasing exponentially. This is obviously unrealistic only happens because the fuel cells don't [yet] care about the H2 and O2 (other than consuming it, that is).
The NaAs happen because temperature runs away and the model for FC performance breaks down at some point. Your FC-2 in the scenario you shared was about 2500°F--which is not physically possible. Temperature increase causes voltage and current to increase which in turn feed back into the rising temperature. This can actually happen--to some degree--but you need reactants for that to be possible.
I have a fix in the works that should prevent this from happening to anyone in the future.