I was trying them out in dev and would like to use them in my next playthrough, but having some slight problems of use with them design wise:

• Power drops over time while open
• Power drops based on transfer (like other AE devices)
• Tooltip keeps moving due to power drain and the % readout is bouncing with the last two decimals of use so like 91.01% to 91% and so on

I understand it is intended as other devices do it, but it is feels panic / race inducing for no reason in this regard
And it is dropping quite quickly really
0.1% per second or so is incredibly fast when you consider the transfer cost
Recommendations:

• I'd do away with the consume power while open. It just makes it feel like a race to do something unnecessarily. And wasteful if nothing was done.
• Unless the extra show hidden tooltips (Or some other config option you have) is enabled perhaps remove the exact power storage amounts and just leave the percentage.
• Keep the transfer energy cost but perhaps review them for the portable cell.