What cable to extend a Tesla mobile charger?

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I need to extend a Tesla mobile charger.
The guide line says you HAVE to plugin to a 3 pin wall socket.
It specifically states you shouldn't use an extension cable.

I saw an American video. One guy uses a very thick extension cable.

I've looked up 'heavy duty' extension cable.
What other 'measurements' do I need to watch our for?

VERY IMPORTANT: I need to be able to put the extension through a letter box. That's really really important!

Currently...
I'm using a single line 10m extension cable - not heavy duty.
I plug into a Belkin Surge protector extension socket that then plugs into the wall socket.

When I've plugged into a wall socket and charged, the wall socket gets hot. Not overly hot, but touching I can feel a raised temperature.

Using my current configuration, the extension plugged into the Belkin is a little warm.

I'm guessing a little warm is better than a hot wall socket?

Thanks.
 
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no expert
but general comments you cannot use a socket outdoors unless designed for purpose this will include protection which will preclude both the plug end or socket end fitting through letter box due to weather protection
now whether a purpose made waterproof compartment outside can reduce the danger with socket and plug fully contained within probably not to regulations probably enough to ease the actual danger to a level you can justify to make it work but off course should not be used ??
 
The safest soloution is to get a proper charge point installed.EV charging at 10A for potentially many hours is pushing the limits of a 13A plug. The plugs attatched to EV chargers often have special thermal sensors that will shut the charging down if the current gets too high, but an extension lead will never have that.

If that is not possible, then I would suggest making up two cables. The first cable would run from a 13A plug to a powercon true 1 socket, the second would run from a powercon true 1 plug to a weatherproof 13A socket. The reason for using two cables is that you won't get a 13A plug or a weatherproof 13A socket through a letterbox, but you will get powercon true 1 connectors through.

For the cable itself I would suggest 1.5mm H07RN-F. H07RN-F is basically the heaviest duty flex you can buy.


I would also add some extra protection round the cable where it went through the letterbox.

Note: to wire the powercon true 1 connectors you will need a T8 screwdriver.
 
The 13 amp plug on a charge lead is designed as an emergency charging device. The problems of charging from a TN-C-S supply are not addressed when using a 13 amp plug, although loss of PEN is not that common, it is possible, so there needs to be protection if the car is not being charges within the equipotential bonded area, i.e. a garage.

We are it seem seeing increased cases of loss of PEN we were alerted to loss of PEN problems early on with EV charging, and it seems the the government departments for the safety want to berry their heads in the sand but the problem will not disappear.

Maybe your supply is not TN-C-S in which case that is not a problem, however it is recommended
BS7671 said:
The load current in any part of the circuit should be unlikely to exceed for long periods the current-carrying capacity of the cable (Regulation 433.1.5 refers). This can generally be achieved by:
(i) locating socket-outlets to provide reasonable sharing of the load around the ring
(ii) not supplying immersion heaters, comprehensive electric space heating or loads of a similar profile frog the ring circuit
(iii) connecting cookers, ovens and hobs with a rated power exceeding 2 kW on their own dedicated radial circuit
(iv) taking account of the total floor area being served. (Historically, limit of 100 m² has been adopted.)
The granny lead is taking near the full output of a 13 amp socket for an extended time, this can overload one leg of a ring final, and it can put stresses on the plug as the fuse is heating up the plug, clearly the plug on the charging lead has been selected to take the heat, likely black as black radiates heat better, and likely large so bigger surface area.

I have since moving into this house with until recently no outside socket, put leads for garden tools out of the cat flap, which is plastic, yet has damaged a couple of extension leads. I have now fitted an upper water resistant socket, still need to fit one for lower side of the house. I have never tried to put a 13 amp plug through a letter box, but likely the door will need opening and closing with it through the door, OK I have 6 outside doors on my house, but that's unusual, and it is the opening and closing of the door which is likely to damage cable.

I got an outside extension lead from Lidi, which does seem to be made from reasonable sized cable, and has flaps on the sockets, but once the flap is lifted to use a plug the water sealing is lost. Having RCD protection is of course a must, and it may require over type A depending on what is in the charging lead, and although with all RCBO that I have if the supply tripped it would not be a big deal, most it seems don't have 14 RCD's in their home, but just 2, so the chance of water with an outdoor supply causing the loss power to items like fridge and freezer is high.

Basic point is if you can afford an EV you can also afford a proper charging point.
 
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No connection with these, other than having picked up the recommendation from the speak ev forums:

You can also order similar made up from tough leads: https://toughleads.co.uk/products/ev-extension-lead and if you order the Powercon connector with it that will be fitted to it too: https://toughleads.co.uk/collection...extension-leads/products/letter-box-connector (chekc that their default position suits, otherwise specify alterative in notes) and also the trailing socket they use, while bulky is marked as suitable for EV use
 
The safest soloution is to get a proper charge point installed.EV charging at 10A for potentially many hours is pushing the limits of a 13A plug. The plugs attatched to EV chargers often have special thermal sensors that will shut the charging down if the current gets too high, but an extension lead will never have that.

If that is not possible, then I would suggest making up two cables. The first cable would run from a 13A plug to a powercon true 1 socket, the second would run from a powercon true 1 plug to a weatherproof 13A socket. The reason for using two cables is that you won't get a 13A plug or a weatherproof 13A socket through a letterbox, but you will get powercon true 1 connectors through.

For the cable itself I would suggest 1.5mm H07RN-F. H07RN-F is basically the heaviest duty flex you can buy.


I would also add some extra protection round the cable where it went through the letterbox.

Note: to wire the powercon true 1 connectors you will need a T8 screwdriver.
No connection with these, other than having picked up the recommendation from the speak ev forums:

You can also order similar made up from tough leads: https://toughleads.co.uk/products/ev-extension-lead and if you order the Powercon connector with it that will be fitted to it too: https://toughleads.co.uk/collection...extension-leads/products/letter-box-connector (chekc that their default position suits, otherwise specify alterative in notes) and also the trailing socket they use, while bulky is marked as suitable for EV use

At what position are you planning to fit powercons?
 
BS7671 said:
The load current in any part of the circuit should be unlikely to exceed for long periods the current-carrying capacity of the cable (Regulation 433.1.5 refers). This can generally be achieved by:
This shouldn't be relevant. The OP is specifically talking about acquiring an extension that is capable of carrying the load. If you're referring to his fixed wiring, how likely do you think it is that it cannot carry 10A?
 
I need to extend a Tesla mobile charger.
The guide line says you HAVE to plugin to a 3 pin wall socket.
It specifically states you shouldn't use an extension cable.

I saw an American video. One guy uses a very thick extension cable.

I've looked up 'heavy duty' extension cable.
What other 'measurements' do I need to watch our for?

VERY IMPORTANT: I need to be able to put the extension through a letter box. That's really really important!

Currently...
I'm using a single line 10m extension cable - not heavy duty.
I plug into a Belkin Surge protector extension socket that then plugs into the wall socket.

When I've plugged into a wall socket and charged, the wall socket gets hot. Not overly hot, but touching I can feel a raised temperature.

Using my current configuration, the extension plugged into the Belkin is a little warm.

I'm guessing a little warm is better than a hot wall socket?

Thanks.
Do not use an extension lead. Ideally don't use a granny lead.
 
Guys... thanks for all the replies.
I'm super confused! And a little lost in some of the acronyms used :)

EV charger: hoping to have installed end of Jan I hope.

But... I still would like a solution to *safely* charge from a granny 3 pin WITH extension through a letterbox.

Weatherproof problems: I've got a plastic box where I have cut notches. It's very waterproof. No danger of water coming in.

Do I still need the tough leads connector? I don't want to mess around and happy to invest in buying if needed.

This is what I am using through the letter box at present: https://www.toolstation.com/1-gang-extension-lead/p95351
And plugged into the mains something like this: https://www.belkin.com/uk/4-outlet-surge-protection-strip-with-2m-power-cord/P-BSV400-2M.html
(The one I have is many years old.)

If I get the tough leads connector, does that solve my problems?

Thanks.

EDIT: @Risteard no choice right now for charging until I get the EV charger installed. While I don't have that, want to be safe as possible of course.
 
The surge protector is just some thing else to over heat, not really required, the extension lead not ideal, but unlikely to cause a problem for the short time it is being used, some charge leads have a RCD built in, but others don't, and you need some protection for the extension lead. So is the home already RCD protected?

As to cover over the plug and socket outside, one it needs to cool, fuses produce heat, and two I have found under the car bonnet my normal battery charger seems to be OK, the bonnet down on the clip so not fully down, protects the plug and socket enough. In an emergency I have put the plug and socket on a brick so not on the ground, then a plastic box upturned on top weighted down by bricks, so will not get wet, but is not sealed so heat can escape. The smallest hole in what you thing is a sealed box, as air expends and contracts, can suck water in, and be worse than being in the open.
 
But... I still would like a solution to *safely* charge from a granny 3 pin WITH extension through a letterbox.

Is this through a letterbox, out onto your drive, or a letterbox leading out across the public footpath?

If the prior, why not fit a proper outdoor socket, on the wall, from which to charge it from?
 
Guys... thanks for all the replies.
I'm super confused! And a little lost in some of the acronyms used :)

EV charger: hoping to have installed end of Jan I hope.

But... I still would like a solution to *safely* charge from a granny 3 pin WITH extension through a letterbox.

Weatherproof problems: I've got a plastic box where I have cut notches. It's very waterproof. No danger of water coming in.

Do I still need the tough leads connector? I don't want to mess around and happy to invest in buying if needed.

This is what I am using through the letter box at present: https://www.toolstation.com/1-gang-extension-lead/p95351
And plugged into the mains something like this: https://www.belkin.com/uk/4-outlet-surge-protection-strip-with-2m-power-cord/P-BSV400-2M.html
(The one I have is many years old.)

If I get the tough leads connector, does that solve my problems?

Thanks.

EDIT: @Risteard no choice right now for charging until I get the EV charger installed. While I don't have that, want to be safe as possible of course.
If this really is only for 2 weeks, I don't like saying it but, do away with the surge protector to reduce the number of connexions to a minimum and carry on with what you have for now. Fuses do get warm when working near their maximum current, it is what they are designed to do but being a lower quality lead keep checking for heating and heat damage. If anything gets hot to the touch other than warm then rethink it.
I'd very likely dispose of the extension lead at the end as they really aren't made for such use.

Be honest with yourself... If this isn't a 2 week arrangement then get something much better; Permaplug plug and socket and minimum of 1.5mm² HO7RN-FF, I'd go for 2.5mm² to keep the losses down.
 
Last edited:
At what position are you planning to fit powercons?
Somewhere along the run, to allow one of the cables to be passed through the letterbox before plugging the two cables together.
 
I saw an American video.
Totally unrelated to items in the UK.
Ignore everything in those videos.

It specifically states you shouldn't use an extension cable.
The plug on the charger unit includes a thermal sensor, so that if the plug overheats, it will switch off and prevent a fire.
If you use an extension lead you are bypassing that protection, as if the extension lead plug overheats it can't be detected, and will then cause a fire inside your house.

Then there is the problem of many extension leads being made of undersized flex barely adequate for intermittent use of a power tool. Use those with a substantial sustained load and they will melt.

no choice right now for charging until I get the EV charger installed.
The choices are
1 - have an external 13A socket installed and plug the charger into that.
2 - drive to a Tesla Supercharger and charge there. Or if there are no Tesla ones nearby, use any DC charger from any other provider.
 

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