I'd like to see a new element called REBT (rechargeable battery). The TMP would decide max charge and life would be how many sparks it has charged. It would be charged by METL and release into INWR. When switched on by PSCN it will release(if it has any life) and turn light brown. When switched off by NSCN it will turn dark brown and not release. It will always charge until life = tmp. If you set tmp to 0 it can charge with no limit. It should be able to be destroyed just like BTRY.
if you know what you are doing with electronics, you can accomplish this without a new element. the tools are out there, we don't really need more. at least not for my purposes
put quite simply, there is not a need for a rechargeable battery element, actually I don't think that we need any more electronics at all really, use the tools out there to create cool stuff. In effect, not having stuff actually makes people be more inventive :)
I know how to make rechargeable batteries with the current elements. It can have unlimited charge. It would only need one space unlike your other rechargeable batteries that take a lot of room.