I’m a bit confused, I’m still using an FM Futaba 7c system with a FP-R1270F receiver, not that I think that matters. I have some new batteries used in telephones, these are 1.5v. I packaged up four of them and get a full charge around 5.5v.. The system came with a 4.8v battery pack, I was wondering if this would work or better yet I have lipo battery packs of 7.2v. Would the higher voltage burn the receiver out?