Hi Neil, I have a J7 PHEV, and I had to get used to the SHS hybrid system on the car, so basically, if your in HEV mode and your battery is say around 9 miles remaining, the petrol engine will do most of the work but it won't charge the battery as you drive, it will just make sure the battery won't deplete to 0%. I normally charge the car at home as it's much cheaper then some of these fast charge stations which have cost me £15 for a full charge, it's quicker then doing it at home though, but pricey, what I do is plug the car into a three pin plug overnight at home, and it takes around 7 hours to get around 54 miles from the battery. The max mileage that you should get from the J7 on a full charge should be around 57 miles.I hope that helps.
