My fuse box is the old style fuses and not a consumer unit will I need to upgrade prior to having a charger fitted?
Not necessarily the case as a standalone consumer unit can be installed, providing your incoming supply and meter tails will take the additinal load.
Fitting a RCD to protect your old off white, black or metal Wylex fuse box, along with swopping the rewireable fuses with plug in MCB’s, may however, be a worthy upgrade, to offer a level of protection, rather than going the whole hog and swopping over to a consumer unit.
Feel free to post a pic of your meter cupboard, if you have any specific questions.