Charging from socket permanently

[jonahjones]

Hi guys,

I have the free 6000 charging miles and have also been charging from our normal 13amp socket in the garage when needed.

I work from home so am finding the combination of the above is currently good enough for me and I don't want the hassle at the moment of installing a proper EV charger at home. (lots of floor boards to lift the route is nasty)

Is there any problem using the socket often? It isn't getting hot and has charged the car fine.

Thanks

 

[OfficialMark_H]

I’ve used the 3 pin socket on both my Teslas for over 3 years, absolutely no issues at all.
I did consider putting in a charger but for the mileage I do it’s not really worth it.

 

[jonahjones]

I’ve used the 3 pin socket on both my Teslas for over 3 years, absolutely no issues at all.
I did consider putting in a charger but for the mileage I do it’s not really worth it.

Thanks. Yeah I currently can run the cable under the garage door and lock it all up which is much neater than having an ugly charger outside. I may just continue with that until my miles run out.

 

[phil4]

I did for many months when I first got my car, it never caused any problems. That said, just make sure you periodically firmly push the plug into the wall socket now and again. Loose connections will warm up and make themselves worse over time.

 

[WannabeOwner]

free 6000 charging miles

Just my 2p-worth:

My guess would be 20 minutes (e.g. 10% to 80%) to get 200 miles ...

... that's 10 hours sat at the supercharger. Assuming 4 miles / kWh that's 1,500 kWh @ 10p for an off peak rate thats £150 - £15 / hour. If charging to "approaching-full" it will be significantly longer than that.

But maybe you have something else you can usefully do whilst at Supercharger, or you use the Free Miles on out-of-range trips (in which case I doubt you, and many/most? others, will actually use up the free miles in time)

 

[LiamPope]

There's nothing inherently wrong or dangerous about this. As you will have noticed, the UMC limits charging to 10 A on a 13 A UK socket as some safety margin against overheating. But you are somewhat depending on the circuit you are using all being up to spec and in good condition. If this is a dedicated circuit to this garage socket, more likely all is OK. If this is a socket on a 32 A ring final then you're depending on every connection on this ring being good. If just one socket has a loose screw this may overheat with sustained 10 A load.

Whether you're strictly allowed to use this as a 'permanent' solution is another matter. I'm not familiar with UK rules and maybe it is 'frowned upon' - I don't know.

 

[GRiLLA]

I would also add that it's less efficient to use a regular plug, you'll get maybe 93% of the power you use arriving at the battery on the UMC, and maybe 97% on a true 32A charge point. The reason is that the car spends longer awake receiving charge I believe, but I'm no expert on this.

It's likely to take a long time to save enough to pay for a home charger installation, but if you are more interested in reducing carbon impact or using solar it can be worth considering.

Whether you're strictly allowed to use this as a 'permanent' solution is another matter. I'm not familiar with UK rules and maybe it is 'frowned upon' - I don't know.

Wiring regs BS7671 would say that it needs to be installed with a socket specifically designed for the job, BS1363-2 and marked for EV use. See

Of course, while that applies to folks installing electrical outlets it's not really something that an end user would consider.

There absolutely is a risk that if a socket hasn't been installed perfectly, has any flaws, or even if the plug isn't connected fully that pulling a consistent 10A load over a long time is a fire risk. I don't really see why anyone would choose to live with that in the long term.

 

[McXtravert]

I spent the first 10 months using the 13A charger whilst we were waiting to move house (no point installing a 32A charger to leave it behind!).

So long as you don't have any cables coiling up you will be fine

 

[WannabeOwner]

There absolutely is a risk that if a socket hasn't been installed perfectly, has any flaws, or even if the plug isn't connected fully that pulling a consistent 10A load over a long time ...

... negates any benefit from the saving of not installing a wall charger

 

[Mullermn]

I've been using the 13A plug for 2 months and it's been fine. It seems that there are real benefits to a proper charger and I am planning to get a one installed but that's not a simple job in my property as it requires wiring upgrades between an outbuilding and the main house before the electrician's happy that a car wall connector [which would draw more current] could be added.

If we have a big travel day the car can sometimes not have fully charged overnight but we worked out that we can always get enough charge added in one night to cover our biggest 'normal' day so that's not been an issue. If it wasn't for the safety benefit of a proper wall connector I might consider not bothering, it's not been as much of a hassle as I thought it would.

 

[Smileysam]

When using a 3 pin plug efficiency is at around 80% so I'm wasting 20% of energy?

Over a long period of time the 7kw charge would pay for it self.

Probably.

 

[Adopado]

A significant issue when using 10A charging is that the slow speed limits your opportunities to take advantage of cheap rate electricity tariffs, because most are limited to just a few hours. I believe something like Intelligent Octopus could work though.

 

[LiamPope]

When using a 3 pin plug efficiency is at around 80% so I'm wasting 20% of energy?

Over a long period of time the 7kw charge would pay for it self.

Probably.

If you're referring to only getting 10 A charging rate from a 13 A plug, this is not loss due to inefficiency - it's just the UMC limiting current draw to 80% plug rating as a safety measure. That 20% is not being wasted. Same as over here in Europe I can only charge at 13 A from a 16 A rated standard Schuko domestic plug. If I simply swapped out a Schuko plug for a blue 16 A commando and swapped out the UMC adaptor accordingly I could draw the full 16 A as there is no such de-rating applied to those sockets.

 

[Mrklaw]

if you have a dedicated socket in the garage is it on its own fuse on the consumer unit? if so maybe it could be checked and if the wiring works - upgraded to support a 32A feed for a charger?

 

[Jason71]

I would also add that it's less efficient to use a regular plug, you'll get maybe 93% of the power you use arriving at the battery on the UMC, and maybe 97% on a true 32A charge point. The reason is that the car spends longer awake receiving charge I believe, but I'm no expert on this.

I think that is more likely to be 90% with a charge point and 85% with a UMC TBH

 

[Mullermn]

I think that is more likely to be 90% with a charge point and 85% with a UMC TBH

I checked Tessie and it reckons I've averaged 89% efficiency on my home (13A socket) charges. However, I presume that Tessie can't know about losses between the meter and the UMC so that may be overly optimistic.

 

[Jason71]

I checked Tessie and it reckons I've averaged 89% efficiency on my home (13A socket) charges. However, I presume that Tessie can't know about losses between the meter and the UMC so that may be overly optimistic.

If you really want to know plug an energy monitor into the wall then compare that with what the car says it has received. 15% is what I have heard. I have compared my 32amp charger and that was around 10% so I can believe it.
Overall I have found the difference between the total electricity consumed charging the car and the total the car claims to have used via the trip meter is about 30%. So while the meters in the car are great for working out driving efficiency and range on a long journey if you want to know what your car is costing you in fuel add 30%. I don't think many people realise the overhead for charging loss, preheat, sentry, Netflix, phantom drain etc adds up to be so much.

 

[Mullermn]

If you really want to know plug an energy monitor into the wall then compare that with what the car says it has received. 15% is what I have heard. I have compared my 32amp charger and that was around 10% so I can believe it.
Overall I have found the difference between the total electricity consumed charging the car and the total the car claims to have used via the trip meter is about 30%. So while the meters in the car are great for working out driving efficiency and range on a long journey if you want to know what your car is costing you in fuel add 30%. I don't think many people realise the overhead for charging loss, preheat, sentry, Netflix, phantom drain etc adds up to be so much.

Yeah. I mean I love the fact that the car is always warm when I get in but it seems to be quite generous with how long it gives itself and it's often sat there having reached temperature for 20 minutes before we actually leave. If I was running a fan heater to heat a cold shed up to 18 degrees for 20 minutes I expect I'd get through quite a bit of power.

 

[tdjohn]

We've been using the supplied charger with an outdoor 3pin for 18 months and 2 cars - we do 20k a year, mainly charging at home. Initially I was going to install a "proper charger" but could not find anyone to install at the time as everyone in the world seemed to want one. Glad now, I just bought a second one that I leave in the boot. I even attached the supplied one to the wall using the Tesla kit. It's been outside all that time, very exposed, no problems.

No idea if it's recommended or advised to leave one of these out exposed to the elements and charge every day.

 

[SageBrush]

Is there any problem using the socket often?

Only that that more use means wear and tear if you are plugging/unplugging. If the EVSE stays plugged in then that problem goes away.

The other issue is that the EVSE is heavy, and if the EVSE is pulling on the plug you will end up with a poor connection which is dangerous.

-----
So ...

• Plug/unplug as little as possible. Never wiggle the plug. Replace the socket (receptacle) if the plug is loose in the receptacle.
• Support the EVSE so that it does not pull on the plug