WARNING -- WARNING Be VERY careful what you plug in to the socket in the glove-box. It shares the fuse with the sidelights and some other items. I found out the hard way when plugging in a battery charger and wondered why the lights stopped working!!!!!!

It will NOT tolerate any reasonable losd!!
Wire in a separate socket WITH AN IN-LINE FUSE (Can be got in Halfrauds)direct to the battery --I have mine on a lead which leaves the socket at the side of the transmission tunnel. It is easy then to plug in either a battery charger or indeed, sat nav or other item when on the move.