MG4 - charging from a 13A socket

[dcsprior]

Hi, I ordered an MG4 (SE Long Range) on Saturday 8th, and am picking it up on Saturday 15th. We won't have a charger fitted by then, so until we do our choices are charge at public chargers (£££) or charge from a 13A socket. So...:

• is it safe to charge from a 13A socket? I've read that it's risky as they're not designed to supply anything like the rated current for a sustained period of time. If it makes a difference the wiring is modern as the the house is 7.5 years old
• Does the MG4 come with a "granny charger"?
• If so, how long is it? Our outside socket is probably just over 10m away, and while there is a socket in the garage (~2m away) that'd mean leaving the garage door open a crack, with something in front of the door to stop it swinging fully open, which isn't ideal
• If it comes with one that's not long enough, is it safe to use with an extension lead or do I need to buy a longer one?

 

[MG Clive]

Hello @dcsprior, welcome to the forum, our @salty is the man to ask about 'granny charging'.

 

[salty]

A 7.5 year old house, should be perfectly safe. The car probably won't come with a Granny charger, unless you can negotiate one. The MG granny charger is 4m long.
To be honest I wouldn't use an extension.
Buy a 10m granny charger.

Oh and,

To the forum. And enjoy your new motor.

 

[siteguru]

FWIW, I use the MG granny unit when visiting my brother ... and I also use a suitably-rated extension cable (with sealed socket). But I only use this setup maybe 3-4 times a year; home charging is from my 7kW EVSE.

If there's no granny unit being supplied with the car, and you wish to purchase one, then I'd agree that getting one that's about 10m long would be better than one which is 4m plus an extension cable. I simply got the extension because my car did come with the granny unit.

 

[dawson2099]

Mine came with a charger in 2023 but the lead was not long enough - a regular 13a extension will trip out - I had to make up an extension with a larger cable - absolutely no issues with charging for a prolonged period - the charger gets warm of course but cuts out when full

 

[siteguru]

My granny unit doesn't get warm at all. And my extension lead barely generates any heat.

 

[kiwi]

If you use the granny charger that comes with the vehicle it will be fine. Despite the 13A UK rating and 10A for Australia and New Zealand (where I live) our outlets are not rated for this current with 100% duty cycle. The relevant standards set a safe limit for continuous duty at 80% of the design value, so that’s ten and a bit amps in the UK and 8A here.

If you have a granny that came from MG you will be fine. It will comply with these restrictions. If you have a third-party portable charger all bets are off because there are people (and some are on this board) who think nothing of turning things up to 11. But that’s another whole topic of its own.

I used a granny for years to charge both an MG ZS EV and our MG4 without issues. There is far far less chance you’ll burn your house down than you would have setting fire to it with the petrol and heat of your ICE vehicle, mower, or weed eater, etc.

 

[EvTek23]

@dcsprior, if you are going down the extension lead option then either ToughLeads,

Electric vehicle leads

Tough Leads products are renowned on EV forums and Facebook groups for their high quality and reliability. Please see our article on safely charging electric vehicles for advice on extension leads. It is the responsibility of the EV user to consider the manufacturers guidance, the safety of the...

toughleads.co.uk

or Industrial Extension Leads,

Industrial Extension Leads ltd

We specialise in the full range of trailing heavy duty extension leads, from high quality 13amp extension leads to 63amp leads used in heavy industry.

www.industrialextensionleads.co.uk

can provide high quality extension leads. Industrial Extension leads use 2.5mm² cable and ToughLeads use 1.5mm² cable with the length of your choice, with or without RCDs depending on the protection you have on that circuit.

 

[Everest]

I love that Aus/US term "weed eater"

Back on topic... my 2p worth...

The safety will depend largely on the quality of the socket you are connecting the granny lead into, rather than simply age of house.

If you are planning on using a granny charger for any length of time, then I'd recommend using a BS-1363-2 EV rated socket, which will a) be compliant with current BS7671 regulations and b) be able to support a sustained 10A charge rate without overheating.

If using a regular (non-EV rated socket), I'd reduce the charge rate to 8A, rather than 10A. And periodically check the temperature of the plug+socket combo. They should remain under 50°C after 2 hours usage and be no longer rising in temperature.

Avoid the use of an extension lead if at all possible. If using one is unavoidable, use one rated for the task, as already linked above.

 

[GaryMG4]

No issues with using 3 pin EVSE here, including one mammoth 28 hour charge, just check nothing gets more than a little warm to the touch. FWIW get a type 2 cable so you can use the CPS destination chargers, they are not that expensive to use and give you another option before your EVSE is installed.

 

[dcsprior]

Thanks all.

If it comes with a charger, then buying a heavy duty extension cable for it is probably going to work out cheaper than paying for public charging.

If it doesn't come with one, then public charging for a couple of weeks is probably going to be the best option. Twice a week I spend 7-9pm just across the road from a charger which is 75p/kWh pre-8pm and 60p/kWh post-8pm

 

[Roger001]

Hi, I ordered an MG4 (SE Long Range) on Saturday 8th, and am picking it up on Saturday 15th. We won't have a charger fitted by then, so until we do our choices are charge at public chargers (£££) or charge from a 13A socket. So...:

• is it safe to charge from a 13A socket? I've read that it's risky as they're not designed to supply anything like the rated current for a sustained period of time. If it makes a difference the wiring is modern as the the house is 7.5 years old
• Does the MG4 come with a "granny charger"?
• If so, how long is it? Our outside socket is probably just over 10m away, and while there is a socket in the garage (~2m away) that'd mean leaving the garage door open a crack, with something in front of the door to stop it swinging fully open, which isn't ideal
• If it comes with one that's not long enough, is it safe to use with an extension lead or do I need to buy a longer one?

The UK now has a new socket standard - "BS 1363-2 EV" for sockets that are approved for continuous 10A inductive loads as found with an EV charger.

Due to the current draw, you can not use extension leads to extend a granny cable/charger. For my needs, I ended up purchasing the 20m granny charger found here

https://voldt.co.uk/products/3-pin-ev-granny-charger-adjustable-8a-13a-2-8kw-charging-cable?variant=49357541867854

Over the last 5 months or so, it has been keeping my car charged as and when required to a total of around 500kWh.

 

[Fogey]

The key thing about use of an extension lead is the wall-socket/13A-plug interface. This can overheat - whether due to an imperfect fuse connection in the plug or just poor contact.

The granny charger's 13A plug will have a temperature sensor to guard against overheating (and possible meltdown - fire even - given the timescales involved). The extension lead won't have this, so has to be treated with caution, and that should probably include running at 6A rather than 10A.

The other thing about using a granny charger is that it won't offer any protection in the event of a (rare) earth fault - unlike a properly installed charge point.

 

[dave99]

The UK now has a new socket standard - "BS 1363-2 EV" for sockets that are approved for continuous 10A inductive loads as found with an EV charger.

Due to the current draw, you can not use extension leads to extend a granny cable/charger. For my needs, I ended up purchasing the 20m granny charger found here

Hmm, if a 13A extension lead can't cope with 9-10A continuous surely it's not fit for purpose? I do think there are some scare stories around to make people buy EV special stuff - surely just making sure nothing is getting warm after an hour is a good indication your equipment is fine in the short term. Loads of people use extensions for granny chargers?

 

[Fogey]

It's not the extension lead itself, as I said, it's the plug at the end - which doesn't have a temperature sensor that is coupled to the charger.

 

[L0rdMike]

I've used a 3 pin charger last 10 months and not had any issues. I often charge mine at 8amps but a socket monitor shows only 7amps drawn.

I bought one of those laser guns to check what sort of temp the plug and socket reached.

More than enough to recover my 45mile day trip.

 

[Fogey]

I should mention that a plug/socket combination can go into unexpected thermal runaway at any time. Keep a watchful eye (and nose). You have been warned!

 

[NikLiverpool]

I would suggest also to buy one of these:

13A UK socket tester with RCD test function

13A UK socket tester with RCD test function. Handy socket tester, ideal for checking the supply to your caravan, EV, hot tub or any other appliance. Particularly useful for checking for the common issue of live-neutral reverse on European campsites. Also great for checking sockets before...

toughleads.co.uk

I use my granny charger quite often since we have 2 EVs and there is the odd night where one of them needs to go on it.
Also whenever we go for a holiday I use the granny charger (always with the house owner's consent).

The kit I attached has highlighted to me some cases where a socket was not fit for purpose....

 

[dcsprior]

The key thing about use of an extension lead is the wall-socket/13A-plug interface. This can overheat - whether due to an imperfect fuse connection in the plug or just poor contact.

The granny charger's 13A plug will have a temperature sensor to guard against overheating (and possible meltdown - fire even - given the timescales involved). The extension lead won't have this, so has to be treated with caution, and that should probably include running at 6A rather than 10A.

The other thing about using a granny charger is that it won't offer any protection in the event of a (rare) earth fault - unlike a properly installed charge point.

Thanks.

Some fag-packet maths says that limiting it to 6A and only charging at times when we're at home and awake, will add more miles than we use (over 250 miles/week added vs under 200 miles/week used)... so if we do use granny charging as a stop-gap until the proper charger fitted (I'm expecting a quote for that today) we should be able to do so with safe-ish limits.

 

[NikLiverpool]

Get proper equipment; check the socket that you will using for the charging and you will be fine.
As with everything; as long proper precautions are taken the risk is minimal.