It has been done, yes, and it works the way we all told you. You have a new bin set up, that's good. But you still need to apply the workaround detailed by Tazz. I repeat the problem: Even if you make the concrifle use your new bin everywhere, it will still display power cells. Because the numbers in the hud are hardcoded...they can't be controlled by cog. The workaround works like Tazz posted. As soon as a player selects the concrifle, it caches the amount of power cells, then sets the amount of power cells to the amount of your new bin. The concrifle then still uses power cells (ignore my post about changing it, this is wrong) - make sure you adjust the consumption rate. If the player deselects the concrifle, the current amount of power cells (which actually is the amount of your new bin) is written back to your new bin (Tazz forgot that step, it is necessary, though) and the power cells are restored to the cached value (the value prior to the selection of the concrifle).
Tazz code repeated and updated:
"Häb Pfrässe, süsch chlepfts!" - The coolest language in the world (besides Cherokee)