we have an older house with a 60amp main fuse. called UK power who came and fitted a 80amp fuse ready for when I get an electric car, whenever that might be. I mentioned that I might need an 100amp, he said if you charge over night you should have no problem, the issue would be if you charged your car during the day, then switched on induction hob, kettle, dishwasher etc. 80 amp should be fine, most fuses have a tolerance built before blowing, 60 -80 amp, 80-100amp.