I've had an electrician install some new wiring for me for our new electric car charger. It is 10mm twin and earth. He's had to join two of these together, he hasn't fully finished yet, but I'm wondering if the join he has made is sufficient. I've attached a photo of his work.
The join is inside a void under our stairs behind some plasterboard. It will be taking a current of 16A for approximately 9 hours at a time. In the future our new car will be taking 30A. I'm a little concerned that this tape job isn't right. Any advice would be great.