It seems weapons or powercells do not have correct energy labels. Today, Arf discovered the Fast Charge Powercell charged while firing a flechette cannon MkII. The FC powercell has 50 charge, the flechette MkII had about 68 EPS. It shouldn't have charged, but depleted. I tested an Ion Blaster MkII to make sure it wasn't just the flechette, and noticed that with around 70 EPS, my Ultra Charge cell depleted very, very slowly, but nowhere near 20 energy per second.

Yep. The powercell recharge rate is correct when considering ships turbo energy use, but it seems to be wrong when trying to figure out how fast a weapon will drain a powercell, based on the energy-per-shot/delay.

Ah, a little math explains the discrepancy.

The game runs the simulation once every 64 ms, increasing the battery at 50*0.064 per frame, which makes sense and is fine.

Now the tricky part.
Since shooting also takes place every 64 ms, the fact that the weapon can shoot once every 88 ms is kinda moot since the game won't let it actually shoot at that rate. Instead it effectively shoots once every 128 ms (the next time quantum above 88 ms).

So, 6 energy per shot and 1 shot per 0.128 seconds (6/0.128) = 46.875 energy per second, which is just under the 50 energy per second power cell recharge rate.

The weapon might as well have a fire delay of 0.128 and it would result in the same firing rate.

So essentially.. some weapons are mislabeled. :p

Thanks for the explanation, ray!

Edit: slime73 does have a point. Is it possible the weapon descriptions could be updated in the future so it's a bit more obvious how much energy a weapon uses?