Granny charger plug burn out

[WoNkY]

There are granny chargers available that have temperature sensors in the plug, these are far safer and will error and shutdown when excessive inlet (13 A) plug temperatures are observed.
In a quick search I found the Third Rock EV charger has this facility and is stated in both the features and specifications.
Looking at the cable between the plug and the electronics unit it will state something similar to: 3 X 2.5 + 2 X 1.5. 5 conductors in total. The 2.5 being the main conductors for L, N, E (2.5 mm sq) and the 2 X 1.5 the two sense wires for the embedded sensor in the plug.
The specifications for the unit I have included. There will be others too with this facility, I've shown the Third Rock unit as a guide.

View attachment 44271

That’s a great safety feature to have.

 

[RCK49]

The one I bought to cover the period before my wall charger was installed has a smart plug fitted.

 

[Lovemyev]

Just to be clear, both these granny units and higher powered wall boxes, are merely a large switching / communication device.
They are not charging units.
Have do have the ability to communicate with the modules of the car, but the actual charging unit that provides energy to the traction battery, is integrated into the car when first built.

 

[Kenp1]

Just to be clear, both these granny units and higher powered wall boxes, are merely a large switching / communication device.
They are not charging units.
Have do have the ability to communicate with the modules of the car, but the actual charging unit that provides energy to the traction battery, is integrated into the car when first built.

That is true, but everyone calls them chargers.

 

[Kenp1]

I had the socket getting hot when I used the Granny charger, I did solve this but I was still checking when I plugged it in. I was glad to get a proper wall box

 

[Ian Key]

I think you need to get one from a reputable UK supplier who you know will meet UK safety regs and not a cheapo that someone has just stamped some numbers into the plug.

EVCables.com build and test theirs in the UK and they come with a 2 year warranty. They will supply them from 2m to 30m in length and the power plug has a temperature sensor.

 

[Lovemyev]

That is true, but everyone calls them chargers.

The same applies to vacuum cleaners, because we insist on calling them hoovers .

 

[Kenp1]

The same applies to vacuum cleaners, because we insist on calling them hoovers .

I think that is going away, even I tend to call it the vacuum now.

 

[WoNkY]

I think that is going away, even I tend to call it the vacuum now.

Or robovacs..

 

[Everest]

Oh no.. here we go again... is that the 4th or 5th one reported on here

I did all the right things, got that installed, and imagine my surprise when it was actually the plug on the granny charger which melted.

No, I can't imagine you being surprised tbh.... I and others have highlighted the issue with BS1363 plugs on here several times already and made the recommendation to only charge at 8A max. See some of my postings here.. EDIT to add - more importantly see my posting below.

MG4 - charging from a 13A socket | MG4 EV (2022 to 2025) Forum
&
MG4 powering other stuff (Vehicle to Load aka ‘V2L’) | MG4 EV (2022 to 2025) Forum

I'd advocate charging at 8A max continuous when using a BS1363 plug or, preferably, use a 16A or 32A commando socket type portable/granny charger if you don't want the cost and complexity of a fixed charge point.

 

[Everest]

O... M... G...

We have had a lot of discussion on here on the importance of having a BS 1363/A socket installed if you are going to use a granny charger at a continuous 13 amps.

I did all the right things, got that installed, and imagine my surprise when it was actually the plug on the granny charger which melted. You would really think that they would have thought of that.

I don't want to come across as "I told you so", but a) I did and b) I think this is important to highlight here to avoid others having potentially lethal situations.

You did not do all the right things. It is NOT safe to use a BS1363 based granny charger at a continuous 13A - end of.

You had been warned. On 14th Sept 2025 you said..

Salty, what was the logic of going for one limited to 10A when 13A is available?

I have charged many nights at 13A/2.7kW and had no problems whatsoever, no heating of components, no cut-outs, and going 30% slower would be a pain.

I replied in the next posting...

Basically for compliance with IET Wiring Regulations (722.55.101.0.201.1i), mandates a BS1362-2 EV compliant socket to supply max continuous of 10A for EV charging.

FYI; 'so-called' 13A sockets are only suitable for 13A for a short duration - e.g. 3 mins. kettle boiling.

Max should be 10A with BS1362-2 EV socket and dedicated final circuit.

Otherwise max 8A continuous use.

Otherwise, this may happen...

Post in thread 'Don't charge from a 3 pin plug when it's 27 degrees outside kids'

Jun 19, 2025

Have you got a picture of the 'granny's' plug?

It wasn't granny's plug thank god. It was an industrial extension cable approx. 25m long to a weather proof socket.

• Yorkshire Hillbilly

• 

See details on this page.. 13A EV Sockets Compliant with BS 1363-2 EV
or here https://electrical.theiet.org/media/2422/bs-7671-2018_a1_2020-inc-corrigendum-may-2020_read-only.pdf

you defiantly replied...

I have now charged maybe 50 times, sometimes from 20% to 80% and it doesn't even get warm.

and my response was...

We seem to be going around in circles

You asked "what is the logic" - I have given you the answer with the technical & IET / BS7671 regulatory reasons behind it.

With all due respect I don't give a **** if you set your house on fire or electrocute your loved ones with your V2L 13A suicide cord or your lack of respect of earthing and RCD from your V2L thread.

Good luck and goodbye

I give up