I take it that the, no reply to my first post means that either no one knows or the information cant be given out by any one other than FrSky. If it had a switching regulator someone would have been singing the longer duration with three cells. They aren't so it doesn't. A large part of the reliability of an item of equipment is that all the parts of it are designed to be used as its operation demands. The PCB mounted battery socket is not designed for unplugging often. A separate charging socket, of suitable design needs to be installed on the outer of the case. If NiMH batteries are used this can be a two pin standard type charging socket & plug with low rate charger. If a two cell Lipo battery is to be used the charging socket & plug must have three connections, because the charger will need to have a balancer and that will require a third connection. The socket & plug must not allow a short between battery terminals when being connected, this rules out jack type sockets. Cannon plug & socket are reliable but a bit on the big side. circular DIN plug & socket would seem to be the best choice but I am not sure their contact system is up this purpose. A D9 plug & socket could be used which could if wired give you triple redundancy. Let me finish with a question, the Alex Datos manual says that the "SD card is better to be formatted as FAT32,". When I did mine I think it said FAT16, will this be a problem when my QX7 arrives?