I have a hybrid, not a PHEV, so I have no experience with charging a PHEV. Probably someone else with experience will pitch in.
I can tell you the time to charge will depend on a number of variables besides the maximum charge rate. Battery charging is not linear (constant rate.)
For the best lifespan of the battery, it is best to not take it below 20% charge very frequently and charging to not much more than 80% most of the time. Do some research on battery charging for maximum life. You will learn more than I can explain here.
Wayne