Before I close up my ceilings I am thinking to install the cable I might need for a future electric car charger installation. The consumer unit is in the middle of the house but I can run the cable along the first floor joists to the outside wall. Or behind the skirting. I have no idea of which cable will be suitable. Does anyone have experience in this?

What revor said. It will need its own way in the CU with its own RCD. I'm not sure how needed an Ethernet cable will be; all the latest chargers I've seen have wi-fi and/or a SIM, but you may as well put a data cable anyway.

The installation needs to be pukka. Remember it will be pulling 30A for many hours at a time each time it is used, not just a few minutes as with a shower or similar.

Posted By: LFShielded cables can presumable help.

Not as much as you might think. They're not usually required in a domestic setting and their earthing requirements can complicate things quite a bit. Plus of course they are more expensive. Bit like Cat 6 with its increased bend radius; not worth it unless you're going to use it IMHO.

You can get power and data in the same cable which makes a neater job where the cable runs externally.

https://www.doncastercables.com/cables/17/77/EV-Ultra/EV-Ultra------Power---Data-Combined/

also aligns with:

Posted By: JontiWhy not just install an empty conduit so you can pull a cable through in the future if needed.

>I have no idea of which cable will be suitable

Installing a new circuit is notifiable work; by all means do it yourself, but you must have the installation approved by your local authority building control (if you can get them to do it). It would be simpler and safer, for a single cable run, to get an electrician to do it and self-sign it off.

> Or behind the skirting. I have no idea of which cable will be suitable

I genuinely have no desire to be insulting, but both of these statements really do outline the level to which you're NOT currently equipped with the prerequisite knowledge to do this work. This isn't something you take a few lines of advice for off strangers on the internet; this is something that electricians study and train for and are then examined on and engage in continued professional development for so they remain up to date

Note, that it's not really about "put a cable on the ceiling and I'll get a sparky to connect it up in 5 years" - the cable choice and route is the critical part; it'd be more sensible to get competent professional advice right now as to which cable and what route it should take, if you plan on connecting it later. No awake sparky will want to connect up a cable they didn't install, or at the very least cannot see the full length of

> Do not have it in contact with or go through insulation to avoid overheating

It is allowed to come into contact with insulation, but the installation method chosen must be suitable for the required current carrying capacity

> it may be prudent to also run a cat5e or cat 6 data cable to the intended outlet position

Yes, though honestly, for the minimal data bandwidth requirements a car charger has it'd be just as well served by hiding a powerline ac/ethernet adapter inside the case and another one plugged in near the router

> Why not just install an empty conduit

Possibly the most sensible advice for the current situation, IMHO. Make it a large duct (75mm mvhr flexi, perhaps) because ducting affects the current carrying capacity of a cable; if your future electrician decides the in-duct installation method requires a cable with an outer diameter larger than the inner diameter of your duct, then there ain't much point installing the duct..

Id go 10mm T & E , that will let you go up to 10Kw at 15m run easily
6mm is a bit tight on longer runs

many of the newer units dont need data connection

https://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html