RCD query

[Herbs]

I've currently got a main RCD in our kitchen which has a a cable going to the garage where there is another mini RCD which powers the lights and sockets in there.

On the main RCD, this uses a 10a switch.

I've just a BMW i3 which I'm waiting for a rapid charger to be fitted but in the meantime I'm charging via the 3 pin plug which, when I plug it in and have the hot tub on, it trips within 5 minutes as I'm guessing it's drawing too much power.

The installers for the rapid charger check all of this but all have a long list of additional charges for various works outside of the scope of the agreed price.

Is it it as simple as fitting a larger breaker, which I could do before they arrive?

[xyz123]

It's not just the breaker but also the cable in entire circuit that needs to be checked and changed if not rated sufficiently..

[Herbs]

Thanks, wasn't sure it was that easy so will just leave it for them to sort then. Just though 10a was very low compared to everything else wired up!