Charging MG4 Trophy LR, how much do you get at home in 4 hrs?

[jpk]

Am I right in thinking that all the words of caution about regular use of a granny charger are still centered around the condition of the socket and the wiring it's connected to so if it was on a new dedicated run from the consumer unit with its own breaker that would be deemed ok.

 

[Adam C]

Am I right in thinking that all the words of caution about regular use of a granny charger are still centered around the condition of the socket and the wiring its connected to so if it was on a new dedicated run from the consumer unit with it's own breaker that would be deemed ok.

When I was reading into using a granny charger I always read people saying about making sure the wiring/sockets in your house could cope with the load. I guess they meant if it was an old house with ancient wiring.

Check the socket it’s plugged into to make sure it’s not getting warm.

Now I don’t know if MG was included in this but I also read that it’s claimed some granny chargers were waterproof, when checked a few were not 100% waterproof.

Again, this isn’t from my own experience as I’ve never used mine, just what I was told by the technician/mechanic regarding how often to use the charger & what I’ve read online.

 

[GhostOfClayton]

I had a problem using the granny charger via an extension on a reel with an in-built trip. It tripped a couple of times (after a couple of hours or so). However, after unwinding the whole lead, it worked fine.

 

[jpk]

I was asking as I might have to charge from a granny charger exclusively in the future if I need to have my 7kW EVSE removed. I had a failed electric supply unlooping last week so might have to get the EVSE removed but I was hoping to use the same dedicated consumer unit and wiring from the EVSE installation and for a 16 amp blue commando socket if I can or at worst a weatherproof outdoor socket. I'll change the MCB/rcbo to suit whichever I end up with. I bought a Tesla UMC/granny charger a while back and that lets me switch from a 3 pin to a 16 amp commando easily

 

[siteguru]

Can you not just limit the charge rate for your EVSE? Does it have an app which supports current limiting? (i.e. in my Wallbox app I can reduce the current in 1A intervals from 32A down to 6A minimum).

 

[Rolfe]

I've been almost exclusively granny charging since I got the car last April and it's been fine. I have a relatively modern house (1996), and the 13A sockets in the garage are metal-jacketed. The garage is on its own circuit. The plug has never even been warm to the touch, even after 24 hours on charge, and when I've inspected the pins they have been shiny, as-new.

 

[tsedge]

Am I right in thinking that all the words of caution about regular use of a granny charger are still centered around the condition of the socket and the wiring it's connected to so if it was on a new dedicated run from the consumer unit with its own breaker that would be deemed ok.

Yes, you are correct.

The main concern isn't that it won't work the first few dozen times - it is that over time (maybe several hundred charges) increased thermal stress in the wiring and sockets will lead to increased resistance and in turn higher temperatures in a cycle that can result in a failure including (worst case) a fire. Precisely at the point where you have gotten used to it working without overheating and no longer think about it.

Other concerns are overloading the circuit through the use of other appliances at the same time, especially with older gauge wiring that wasn't ever intended for high continuous load applications.

A dedicated circuit eliminates these problems.

Other dangers can still remain - such as the use of non-weatherproof extension leads or coiled extensions.

 

[jpk]

Can you not just limit the charge rate for your EVSE? Does it have an app which supports current limiting? (i.e. in my Wallbox app I can reduce the current in 1A intervals from 32A down to 6A minimum).

I'm gonna ask my dno if they'll accept me limiting the charge rate. They allowed dynamic load balancing as a temporary measure but not as a permanent solution which I think is crazy as that's exactly what the CT clamp is able to do and another advantage to having smart chargers. I can adjust the amps in increments of 1 so can be very specific if they stated an oddball max allowable rate. Makes no sense to me and feels their standpoint is a little antiquated!

 

[Loveclose]

Been with Octopus Intelligent Go via the Ohme Home Pro since the start of my EV experience just over a month ago
I think most am't of charge achieved overnight has been around 48 or 52%.

Most of the time, the charge start is delayed until 2300hrs, sometimes 2330. Charging finishes around 0600 or 0700, depending only on what I set up in the app.
It works.
However, I've yet to see the start of the charge occur before my official overnight cheap rate time.
Costs are incredibly cheap. Miles purchased running at less than 2p pm. Miles actuary used costing around 2.4p pm. Spent justover a tenner.
Previously, I'd top up my Qashqai at least twice a month, costing £45 each time......

 

[Tig170]

My experience of granny charging is not good (I've only done it about 10 times since sept 2022), as the 10 amp is not enough to fuse the plug, but enough to cause the plug to get very hot, as the fuse can get soo so hot, without fusing. Granted this was not directly the MG4 charger, but plugged into a short 1m-extension 4-way socket (nothing else plugged in aside from the MG4 charger - but it was a moulded plug to standard) (which was supposedly rated to 3000w - with all the UKCR CE BS1368/A) - so just use with extreme caution ⚠ - and dont use extension leads (even 1m ones)! - This was just after an hour during the day (when I was working at home), so was lucky as could smell the burning

 

[Rolfe]

Ouch! And yet mine will do 24 hours without even getting warm.

 

[Martinonline]

I use a granny charger with a 5m single extension cable plugged into an outside socket on a 20amp circuit. The plug gets warm but not excessively so and has shown no degradation over the last year. It appears that the bottom of the fuse holder has burnt the most so it could be that the cable terminals inside the plug were not tight enough.

 

[Lovemyev]

I use a granny charger with a 5m single extension cable plugged into an outside socket on a 20amp circuit. The plug gets warm but not excessively so and has shown no degradation over the last year. It appears that the bottom of the fuse holder has burnt the most so it could be that the cable terminals inside the plug were not tight enough.

What is the cross section of the extension cable that you are using ?.

 

[Martinonline]

I do not know what the cross-section is except that it is not a heavy-duty cable and is not on a reel. I attach images of the plug in the outside socket and the connected cable socket in the waterproof box that I use to house the granny charger for charging in the rain.

 

[Jomarkh]

I do not know what the cross-section is except that it is not a heavy-duty cable and is not on a reel. I attach images of the plug in the outside socket and the connected cable socket in the waterproof box that I use to house the granny charger for charging in the rain.

Is there any writing along the length of the cable which tells you what type it is?

 

[Lovemyev]

I am going to make a few assumption here.
1) It’s the orange plug on the extension lead that is showing signs of heat and not the black plug on the Granny unit ?.
2) The orange flex, is it 1.5mm ?.
It should be marked on the external wall of the flex.
If it is less than 1.5mm replace it now.
Over a 5m distance 1.5mm dia cable should fine, but my own personal preference would be to use a 2.5mm dia cross sectional flex.
This maybe seen as a bit of over kill here, but the Granny unit is pulling a lot of load over a long period of time.
This is when the heat will be generated.
The flex on the Granny unit is of a larger cross section dia and is less likely to become warm / hot.
The black plug on the Granny unit is of the high quality moulded heavy duty type.
If heat is affecting this black plug, then I would have to question the quality of the orange socket outlet.
If it’s the orange three pin plug that is getting hot, then check the terminal connections or question the three pin plug or even the grey outside socket outlet itself.
If the black moulded plug becomes damaged by heat, it is not really designed to be replaced.
After the Granny has been in use for a couple of hours, it is expected that the plug top will feel warm to the touch, if it is hot then some further investigations are needed to prevent any further damage.
If the plugs become tight / difficult to remove from the outlets, check for any signs of brown scorching / witness marks to either the outlets or the pins of the three pin plugs, this is not acceptable.

 

[Martinonline]

Thank you for the guidelines and advice. If I might take issue with one point - the orange plug is only warm to the touch not hot and is only slightly warmer temperature as the charger plug even after many hours charging. It shows no signs of heating damage. I always check the cable for damage, keep the plug pins clean and intend to examine the outside socket internally when the weather improves. Being an outside socket is advantageous to keep temperatures low. I thought putting the charger in the weatherproof box would cause heating problems but there is no evidence of that. Again the box is outside.

EDIT: Just re-read the warnings in the underside of the granny charger, very interesting. It recommends replacing the mains socket used for charging every 3 years as well as recommending 'an AC balanced charge of at least 9 hours per month'.

 

[Rolfe]

One of the things my electrician said was that having metal-jacketed sockets, plus these being inside the (pretty cavernous) garage where it's cool and out of the sun (when we get any) was helpful. There's no doubt that in summer it's cooler inside the garage than out.

 

[tonygm]

Might be worth joining the myenergi users group. They helped me when I first got my Zappi charger.

myenergi

The place for myenergi customers, supporters and fans to meet, discuss, provide feedback and share ideas

myenergi.info

Thanks for suggestion. I will try that.

 

[WibbleWobble]

Probably a dumb question, but does the MG4 come with a 13 Amp (10A in reality) charging lead supplied with the car ? Mine is due to arrrive soon and I need to know if I should go out and buy one for trips to see my Granny . I already have a 32A charge point.