Thank you so much for the update.. they are really helpful points. Updates on the points 1. I will look into that. 2. According to the Manual, the Slave should be 0000 and Master 0100 .. but i am also not 100% sure on that. 3. I have checked the Web to try and see how to check the Firmware.. but need Wifi dongle. (might have to make another plan). Currently the older battery is the Master (the difference between them is 14 Cycles. thus not big).. If i move the Master.. do i need to move the Comms cable only to the new master 4. Yes... that is correct 5. I dont think they were both at the same level.. i will try that. The Raspberry Pi is currently on the Master :)