I just extended my electrical installation to charge the EHS I ordered , and what I noticed was the following. I have 25A fuse for the car charging outlet. But standard outlets are rated 16A (Belgium) so I think that's the possible culprit in the getting warm problem of the granny charger plug. I'll check when i have my car.
In the U.K. if you plug the “Granny” into a standard 13 amp three pin plug outlet, then after charging for a few hours, you will find that the top of the three pin WILL get warm to the touch.
Not that hot that you can not touch it, but it WILL get warm.
More so on the right hand side of the plug, where the 13 Amp inline fuse is located.
Ideally the 13 Amp socket outlet used for use with the “Granny” would be on its own dedicated circuit to avoid overloading the general socket outlets around the house.
A wall box is a much better long term solution to be honest.
Retiring the “Granny” for use when no other chargers are available.
I only use my “Granny” now, for when we are going away for a few days, when I know the charging infrastructure is going to be very poor.
Everybody has a three pin socket outlet, but not everybody has a wall box to use !.
I know a lot of people use the “Granny” unit day in and day out without any problems.
But I don’t see this a long term solution.
If they fail and need replacing, they are really expensive from the dealers.
You could well be over half way to the price of a wall box, to replace it.
Wall box is the way to go and then have the “Granny” as a back up unit, should your wall box have an issue.