7Kw public chargers - how useful?
Discussion
Frimley111R said:
A car communicates with an EV charger via a data link in the charging cable. No data link, no charging. How does a Commando socket do that? It just has 32A, nothing else.
People who say home EV chargers are a massive rip off are people who have no idea about them, what they involve, how they work, the electrical regs required, etc. It's like saying that a Ford Fiesta is a massive rip off at £20k+.
An EV charger is effectively a life long 'petrol pump'/fuel supply for your home and some people seem to want to try a budget DIY option. Just look at that Commando socket vs. a proper charger. It looks ... well, you can see how it looks.
As with everything, someone will always try to DIY/budget solution it and that's fine assuming it is safe...
I know what an EVSE does. It's not magic. But perhaps there's a better way to think of it than a bodged DIY wallbox. What if I said you're building a faster granny charger?People who say home EV chargers are a massive rip off are people who have no idea about them, what they involve, how they work, the electrical regs required, etc. It's like saying that a Ford Fiesta is a massive rip off at £20k+.
An EV charger is effectively a life long 'petrol pump'/fuel supply for your home and some people seem to want to try a budget DIY option. Just look at that Commando socket vs. a proper charger. It looks ... well, you can see how it looks.
As with everything, someone will always try to DIY/budget solution it and that's fine assuming it is safe...
By your logic granny chargers shouldn't exist, because 3-pin sockets "just have 13A" and nothing else. How does the car communicate with your 13A socket? Easy, the cable has the "magic" built in. You can get exactly the same set up with a type 2 to commando cable, just faster. As I said, these cables are about £250, far cheaper than a EVSE box.
The commando socket solution is just like building a 7kW granny charger. You're installing a socket, no different to installing a 13A 3-pin socket, which people do themselves at home every day. It's just rated higher, and has a different physical presentation to match the rating. Think of it like a faster granny charger rather than a bodged DIY wallbox, and surely it makes sense?
I've checked the new Building Regs for chargers (Part S) and the various technical requirements and standards, and the definitions do not exclude this solution any more than they ban granny chargers. This would probably not work as an installed solution on a new build (although more because they didn't think to describe this solution than because it's specifically prohibited), but there's nothing stopping you doing this to your existing home.
CharlieAlphaMike said:
Road2Ruin said:
It's not a grand and the chargers have a lot more flexibility re charge times, lockable etc. Also I am pretty sure you got yours signed off by building regs, which will have cost a bit. 
MK Commando (switched) units are lockable. I don't know about all EV's but I know you set charge limits/times on some if not all. Installation of any electrical circuits is a different matter. As far as I recall, adding to an existing circuit is fine but installing a new circuit should only be done by a qualified electrician.
Will take me less than 10 mins to remove it if we sell or get a mate round to sign whatever you're supposed to sign.
I have since added a small bracket to lock the cable to.
With the money I've saved I'll be able to drive the car for the duration of the lease effectively for 'free'.
An extra benefit is you can buy a commando to 3 pin adapter and you've got a charger you can take to your mates, or the Airbnb.
This is my cable, current is adjustable, you can get a 32A cable but I went for 16A as I can use a 16A plug for other stuff. It's never an issue, it will still fully charge overnight.
If I think the cabling is old or dodgy then I knock the current down.
Edited by ChocolateFrog on Wednesday 27th July 11:18
Frimley111R said:
A car communicates with an EV charger via a data link in the charging cable. No data link, no charging. How does a Commando socket do that? It just has 32A, nothing else.
People who say home EV chargers are a massive rip off are people who have no idea about them, what they involve, how they work, the electrical regs required, etc. It's like saying that a Ford Fiesta is a massive rip off at £20k+.
An EV charger is effectively a life long 'petrol pump'/fuel supply for your home and some people seem to want to try a budget DIY option. Just look at that Commando socket vs. a proper charger. It looks ... well, you can see how it looks.
As with everything, someone will always try to DIY/budget solution it and that's fine assuming it is safe...
I think those advocating the chargers vs commando + 32A charger for £250 are those who have no idea or a vested interest.People who say home EV chargers are a massive rip off are people who have no idea about them, what they involve, how they work, the electrical regs required, etc. It's like saying that a Ford Fiesta is a massive rip off at £20k+.
An EV charger is effectively a life long 'petrol pump'/fuel supply for your home and some people seem to want to try a budget DIY option. Just look at that Commando socket vs. a proper charger. It looks ... well, you can see how it looks.
As with everything, someone will always try to DIY/budget solution it and that's fine assuming it is safe...
Commando socket was <£150 installed by a qualified electrician, and charger £250. I have all the control I need (timing, charge rate, can control remotely via the car) and have a separate socket in the garage and by the front door so can charge where I like without paying 2x. The sockets are inside the garage and under a bench so no visual impact (in fact smaller size means more flexibility).
It’s worked perfectly for all of my chargeable cars (i3, i8, mini, Range Rover).
My socket isn’t lockable but frankly I don’t care, if there’s someone wandering round private land to steal stuff I’m guessing going with a 32A charger and EV to steal some electricity is one of the better outcomes for the homeowner!
Of course I’d love to be proved wrong if there’s a hidden benefit of an installed charger that will be useful to me…
somouk said:
CharlieAlphaMike said:
MK Commando (switched) units are lockable. I don't know about all EV's but I know you set charge limits/times on some if not all.
Installation of any electrical circuits is a different matter. As far as I recall, adding to an existing circuit is fine but installing a new circuit should only be done by a qualified electrician.
If the circuit is to be used for a car charger then it needs to meet the regs for that, doesn't matter if it's a dedicated car charger or a commando socket. Installation of any electrical circuits is a different matter. As far as I recall, adding to an existing circuit is fine but installing a new circuit should only be done by a qualified electrician.
With regards to the original OP, I use the 7KW charger at Tesco quite a bit when shopping, the hour or two top up while we're there for free is a useful top up. Wouldn't bother at a services or anything where I would only be there for 15-20 minutes though.
Frimley111R said:
A car communicates with an EV charger via a data link in the charging cable. No data link, no charging. How does a Commando socket do that? It just has 32A, nothing else.
People who say home EV chargers are a massive rip off are people who have no idea about them, what they involve, how they work, the electrical regs required, etc. It's like saying that a Ford Fiesta is a massive rip off at £20k+.
An EV charger is effectively a life long 'petrol pump'/fuel supply for your home and some people seem to want to try a budget DIY option. Just look at that Commando socket vs. a proper charger. It looks ... well, you can see how it looks.
As with everything, someone will always try to DIY/budget solution it and that's fine assuming it is safe...
Which begs the question, why do EV manufacturers offer various options for connecting the charge cable? Including the option to connect via a basic 13A 3 pin plug/socket?People who say home EV chargers are a massive rip off are people who have no idea about them, what they involve, how they work, the electrical regs required, etc. It's like saying that a Ford Fiesta is a massive rip off at £20k+.
An EV charger is effectively a life long 'petrol pump'/fuel supply for your home and some people seem to want to try a budget DIY option. Just look at that Commando socket vs. a proper charger. It looks ... well, you can see how it looks.
As with everything, someone will always try to DIY/budget solution it and that's fine assuming it is safe...
As for communicating with the car. It's the car that does the work as far as charging is concerned. The charge station (whatever charge 'box' you use) is simply a power source.
CharlieAlphaMike said:
somouk said:
CharlieAlphaMike said:
MK Commando (switched) units are lockable. I don't know about all EV's but I know you set charge limits/times on some if not all.
Installation of any electrical circuits is a different matter. As far as I recall, adding to an existing circuit is fine but installing a new circuit should only be done by a qualified electrician.
If the circuit is to be used for a car charger then it needs to meet the regs for that, doesn't matter if it's a dedicated car charger or a commando socket. Installation of any electrical circuits is a different matter. As far as I recall, adding to an existing circuit is fine but installing a new circuit should only be done by a qualified electrician.
With regards to the original OP, I use the 7KW charger at Tesco quite a bit when shopping, the hour or two top up while we're there for free is a useful top up. Wouldn't bother at a services or anything where I would only be there for 15-20 minutes though.
CharlieAlphaMike said:
...
As for communicating with the car. It's the car that does the work as far as charging is concerned. The charge station (whatever charge 'box' you use) is simply a power source.
Almost. The car won't charge unless it can talk to the supply, which is why the granny cable has a ICCB (In Cable Control Box). Same as the faster commando cables. The ICCB takes the place of the wall box, so you still have all the communication bits. As for communicating with the car. It's the car that does the work as far as charging is concerned. The charge station (whatever charge 'box' you use) is simply a power source.
There is no reason to have the control built onto the wall. There is nothing missing in the commando socket + ICCB cable when compared to a wall mounted EVSE.
rewild said:
CharlieAlphaMike said:
somouk said:
CharlieAlphaMike said:
MK Commando (switched) units are lockable. I don't know about all EV's but I know you set charge limits/times on some if not all.
Installation of any electrical circuits is a different matter. As far as I recall, adding to an existing circuit is fine but installing a new circuit should only be done by a qualified electrician.
If the circuit is to be used for a car charger then it needs to meet the regs for that, doesn't matter if it's a dedicated car charger or a commando socket. Installation of any electrical circuits is a different matter. As far as I recall, adding to an existing circuit is fine but installing a new circuit should only be done by a qualified electrician.
With regards to the original OP, I use the 7KW charger at Tesco quite a bit when shopping, the hour or two top up while we're there for free is a useful top up. Wouldn't bother at a services or anything where I would only be there for 15-20 minutes though.
Apart from public chargers or Tesla Superchargers where payments are calculated, loads split or charging is limited, there's nothing special about a home charger. Certainly nothing that can justify the extra expense.
Using a Commando unit with RCD/RCBO protection (knowing exactly how well made MK Commando units are) would always be the preferred option for me.
Mark V GTD said:
I presume one of these 32A 'Commando' outlets requires to be wired with 6mm cable direct to the consumer unit (same as a cooker circuit)?
Not necessarily. It depends how much current you're going to draw. I can change the amount of current I draw on my car. I think to as low as 6A (although I've never set it that low). 32A is the rating of the unit. Think of it as a light fitting with a max 40W lamp recommendation. That doesn't stop you from using a 25W lamp but you'd I'll advised to pop a 100W lamp in (if 100W lamps actually still exist 
).If in doubt, it's always good to speak to an electrician of course
CharlieAlphaMike said:
Mark V GTD said:
I presume one of these 32A 'Commando' outlets requires to be wired with 6mm cable direct to the consumer unit (same as a cooker circuit)?
Not necessarily. It depends how much current you're going to draw. I can change the amount of current I draw on my car. I think to as low as 6A (although I've never set it that low). 32A is the rating of the unit. Think of it as a light fitting with a max 40W lamp recommendation. That doesn't stop you from using a 25W lamp but you'd I'll advised to pop a 100W lamp in (if 100W lamps actually still exist ).If in doubt, it's always good to speak to an electrician of course
Blue commando plugs (57mm) with 3 pins are rated for 230V single phase, and 32A, so you MUST install the sockets with wiring which can cope with that. A device with a blue plug which fits this socket can draw 32A, and signifies to anyone passing "It's totally fine for me to plug my 32A load in here!" and it should be safe for them to do so.
The colour scheme, pin count, plug housing size etc all signify different ratings. To use fit a socket which means one thing but can only cope with less is really really really really bad.
I don't disagree with the "speak to an electrician" bit.
Edited by rewild on Wednesday 27th July 15:25
The main "benefit" from a properly installed EVSE on your wall instead of a basic socket is the ability of that unit to detect ground faults and disconnect your car in that event.
This however, despite being a fundamental part of the latest electrical regulations is pretty pointless in the real world as if there is a ground fault, everything metal in your house will be live and the regs don't protect from that, so the first time you touch your taps, sink, toaster, bath, radiators or anything else you're getting shocked anyway.
Most modern cars are so well protected from corrosion that actually touching a conductive metal surface is really surprisingly hard, every thing is plastic, painted, plated or trimmed these days. My BEV is an I3, so with that's plastic bodywork and carbon tub this is doubly pointless.
I use a 32A socket and openEVSE:
https://www.openevse.com/
and have done for 7 years with no issues.
This however, despite being a fundamental part of the latest electrical regulations is pretty pointless in the real world as if there is a ground fault, everything metal in your house will be live and the regs don't protect from that, so the first time you touch your taps, sink, toaster, bath, radiators or anything else you're getting shocked anyway.
Most modern cars are so well protected from corrosion that actually touching a conductive metal surface is really surprisingly hard, every thing is plastic, painted, plated or trimmed these days. My BEV is an I3, so with that's plastic bodywork and carbon tub this is doubly pointless.
I use a 32A socket and openEVSE:
https://www.openevse.com/
and have done for 7 years with no issues.
I live a 5-10 minute walk from my local Tesco which has no restriction on parking (there may be a sign, but it is not enforced).
A couple of times I've parked my works Tesla at these chargers, walked home, then gone back to get it later in the day. I'll only do this when the shop is closed (ie. Sunday afternoon / evening), that way I'm not inconveniencing anyone else, but taking advantage of it whilst it's free. I can't see it being sustainable forever!
A couple of times I've parked my works Tesla at these chargers, walked home, then gone back to get it later in the day. I'll only do this when the shop is closed (ie. Sunday afternoon / evening), that way I'm not inconveniencing anyone else, but taking advantage of it whilst it's free. I can't see it being sustainable forever!
rewild said:
Context is everything.
This.The other weekend I did a day trip from Milton Keynes to the New Forest. Spent some time driving around the New Forest doing various walks. Stopped at a hotel for afternoon tea, hooked the car up on their 7Kw charger for a couple of hours which gave me enough range to get home without worrying about traffic jams. Arrived home with plenty of range available. Was a no brainer to hook up whilst we were there. Of course a super rapid charger would have been nicer but a fast charge is fine for a graze whilst you are visiting somewhere.
Max_Torque said:
Thank you so much for this! What a great project.rewild said:
Max_Torque said:
Thank you so much for this! What a great project.https://raron.eu/product-category/cc/
I think they make perfect sense for supermarkets. On a big shop you'll probably make back as much as it took to get there, if not more. Because I'm weird I've actually sought out Tescos in preference simply to plug in, even if I might only get a negligible amount of charge there.
From the supermarket's perspective - they're not spending a fortune on a loss leader. They're offering an mild incentive to shop there that will probably cost them less in electricity than they'll make from the customers spending a bit longer there (particularly if they have an onsite cafe that the EV owner might be inclined to go to).
It's something for nothing at the end of the day. I'd sooner see multiples of 7kW chargers at a Tesco than a single rapid charger that only one person can use.
From the supermarket's perspective - they're not spending a fortune on a loss leader. They're offering an mild incentive to shop there that will probably cost them less in electricity than they'll make from the customers spending a bit longer there (particularly if they have an onsite cafe that the EV owner might be inclined to go to).
It's something for nothing at the end of the day. I'd sooner see multiples of 7kW chargers at a Tesco than a single rapid charger that only one person can use.
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