9 hours per day, up to 10 twice a week in Europe, but most countries limit trucks at 80 km/h, with some limiting them at 90.

But you also have to take a break of at least 45 minutes after 4.5 hours of driving at most. So you could use that break to charge. That's why it's unlikely you'd ever need to do 700 km in one go. You'd need ghost drivers whose cards to use, basically.