the connection plug of the two son of this battery was upside relative to my Tom Tom One original sheet on which it is to be connected. It could therefore not directly connect the 2 red son together and two black son together by connecting two pins. When I connected the cards as such, my Tom Tom was not working. So I had to cut the 2 son of the battery (2cm of the plug to make a splice) to attach them (with adhesive tape for electrical wires) then back to their card but by swapping! I then reconnected the two sheets, and reassembled the Tom Tom ... since that works flawlessly!