EV Charge Point DIY

[Adam2]

Am planning on getting an EV so need a charge point at home. But we're building a new place so don't want to spend more than we must so wondering if I can install this myself with 10mm cable as it's 32a and get an electrician in to connect to consumer unit. Any issues??? 

 

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F283674349013

 

[PeterW]

I've considered the same and looked at this one at £229

 

QUBEV Charger

[Adam2]

Looks good @PeterW - are you eligible for the rebate as it looks like you can get an install for about 300 after rebate anyway so not a lot more than buying that part and they do all the work. I was just looking at the part as I figured would save £100 or so but maybe even then not worth it as the features of the one in this link look quite good.

https://www.chargedev.co.uk/at-home/

 

[Jeremy Harris]

I've DIY'd three charge point installations now, including building the charge points themselves.

 

The OLEV grant only applies to "smart" charge point installations, and like all subsidies it seems that the installers are absorbing the grant money as a bit of additional profit.  The grant is 75% of the installed cost up to a maximum grant of £500, and guess what?  No installers claim less than the full £500...

 

There are a few charge points around for ~£200 to £250 or so that work just fine.  On top of that there will be the cost of a run of 6mm² cable (maybe 10mm² if it's a long distance), plus an enclosure with a Type A RCBO, a couple of henlys and lengths of tails cable.  Not wise to connect a charge point to a spare way in an CU, IMHO, as it will draw 32 A for several hours on end, and things may get a bit warm in there.

 

Another thing to consider is whether you want to install a tethered charge point or a non-tethered one.  Tethered ones are easier to use, just unhook the cable and plug in, but they look a bit uglier, as there will be a few metres of hefty cable coiled up around the thing.  A socketed unit means getting the lead out of the car every time you want to charge, and plugging it in both ends, but does tend to look a bit neater.

 

Personally I'm not a fan of smart charge points, for a few reasons.  Firstly, on a point of principle I object to data being collected about my car charging habits, for several reasons, not least of which being that a failure to charge for a few days would be a reliable indicator that I'm not at home.  Secondly, users of various makes of smart chargers are reporting that, like pretty much all app controlled kit, reliability can be a bit flaky.  Tales about of cars not charging as expected, charge rates being randomly reduced, user interfaces falling over and some charge points refusing to play nicely with some devices.

 

The bottom line is that a charge point is just a switched power outlet, and doesn't need anything other than a means to turn it on and off.  I prefer being able to do this easily and reliably with a switch, as it then needs no 'phone, internet connectivity, sanction by whatever authority controls the smart features, etc in order to work.  I want to be sure that my car charges when I want it to, not when someone else decides I'm allowed to.

[Ed Davies]

OTOH, having your charger track the spare output from your PV panels would be nice (and doesn't need any connection external to your household).

[Alex C]

8 minutes ago, Ed Davies said:

OTOH, having your charger track the spare output from your PV panels would be nice (and doesn't need any connection external to your household).

https://myenergi.com/product/zappi/

[Jeremy Harris]

10 minutes ago, Ed Davies said:

OTOH, having your charger track the spare output from your PV panels would be nice (and doesn't need any connection external to your household).

 

 

No it doesn't, but a condition of the OLEV grant is that you have to have a charge point installed that does have external data gathering and charge control  capability, much like a smart meter.  You can't get a grant-funded installation without this feature.

 

My charge point has a (manually switchable) option to charge when there is excess PV available, but the rather limited J1772 signalling protocol used for both a safety interlock and signalling maximum available charge current is a restriction.  The minimum charge current is 6 A (and most cars are very inefficient when charging at 6 A), so any PV system needs to be generating in excess of this before car charging can start.

 

My implementation takes a pragmatic view that partial charging from excess PV is always beneficial if the cost of charging is lower than the off-peak rate.  I used to adjust the charge current on the fly to allow for this, but that was flawed, because the car onboard charger was both slow to respond and had a fairly long latency (it didn't respond quickly to the control pilot increasing duty cycle to signal that more current was available).  I've ended up with a fixed solar charge current setting of 12 A, together with a bit of code that keeps the car charging for as long as the cost is less than 8p/kWh.  If the charge cost stays above 8p/kWh for 20 minutes, then the car stops charging until either the PV starts to generate more, or until the next off-peak time period.

[Adam2]

 

40 minutes ago, Jeremy Harris said:

No it doesn't, but a condition of the OLEV grant is that you have to have a charge point installed that does have external data gathering and charge control  capability, much like a smart meter.  You can't get a grant-funded installation without this feature.

 

Great thanks @Jeremy Harris for the info re the rebate as that would rule me out also  if I have to connect this for external data visibility. I wonder how this works though - presumably you must connect it to your home LAN over wifi - which can easily be disabled at a later date if wanted.

 

Maybe as I'm only living in the current house for another year or so maybe I could suffer the data issue if it means it's less hassle than DIY and only slightly more expensive

[Jeremy Harris]

A smart charge point usually connects via wifi, although I believe some can (rather dodgy in my view) accept an Ethernet cable. If there's no connection, then there may be be no way to turn the charge point on and off, schedule off-peak charging, etc, as I believe it's managed via an app.

 

I have concerns as to whether security has been adequately addressed with smart charge points, TBH.  At least one system is so deeply flawed that it created a bit of a stir when this was exposed (although I believe it's being addressed now, although this isn't much consolation to the few thousand who already have the Raspberry Pi version): https://www.pentestpartners.com/security-blog/pwning-a-smart-car-charger-building-a-botnet/

 

 

[Adam2]

OK - I'll ping a msg over to an installer co and see what they say when I tell them there is no wifi at the charge point location. I bet they will still like the money ?

 

[Jeremy Harris]

Be interesting to find out how much functionality a smart charge point has with no connectivity.  Hopefully there may be some ability for it to work as a basic charge point without any connectivity, but it could be a bit of a nuisance if it ends up being disabled if it cannot connect.

 

Some of the more basic smart charge points may be a better bet than something more sophisticated, as I get the feeling that the basic models may have had the required smart functionality installed as an add-on to an existing design.  If so, then it seems likely that they may well work with no connectivity without a hitch.

 

One option is to just get a commando outlet installed, then use a portable charge point.  Some can charge at 32A (the Tesla UMC allows this) and a portable charge point is a useful thing to have (although most EVs come with one, normally limited to 10 A maximum).   You can buy a portable charge point that will deliver up to 32 A and plugs into a commando outlet, for about £250 or so (I've seen cheaper ones around, just can't find them right now).  Wiring in a 32 A commando might not be a very costly job.

[joth]

39 minutes ago, Jeremy Harris said:

At least one system is so deeply flawed that it created a bit of a stir when this was exposed (although I believe it's being addressed now, although this isn't much consolation to the few thousand who already have the Raspberry Pi version): https://www.pentestpartners.com/security-blog/pwning-a-smart-car-charger-building-a-botnet/

 

 

I enjoyed reading that, not least because half way through it I realized I knew the author. He has some great exposés of DIY home alarm systems on that blog too. (hmm now there's a thought - we should get him onto all this keyless car theft)

[Adam2]

OK so it looks like (from one supplier/installer at least) that you may not need a data connected charge point to qualify for the rebate.

 

This is a transcript of the chat

 

[SteamyTea]

Spotted this new charging point today.

Be ok for a very short car with a good turning circle.

[Adam2]

On 14/11/2019 at 18:49, Jeremy Harris said:

Wiring in a 32 A commando might not be a very costly job.

Am super interested as just pressed "buy" on a used Tesla  - think I saw you on the Tesla forum Jeremy :-)  Thinking that maybe the quickest way to get a charger in place would be a self/electrician installed socket that would work with the 7.2kw  32amp. My install is as easy as it gets as the unit would go on the side of the garage which has the consumer unit & meter in. Though will call a couple of install companies and see what they can do in next couple of weeks. Quite excited!

[Jeremy Harris]

To charge at 32 A with the Tesla UMC you may have to buy the optional 32 A commando adapter.  Some cars came with this, some didn't (mine just has a 13 A plug adapter and a 16 A commando adapter).  Not a major issue, as Tesla sell the 32 A commando adapter lead for ~£40, I think.

[Adam2]

So to continue the EV journey... buying used from Tesla is painful in the extreme, not enough people handling orders so 2 weeks after deposit paid only 1 email, no calls or emails answered and no delivery date of course. But, the price is great compared to alternatives so will have to be pleased with that for now!

 

On the charger front some great news - that is installed. ChargedEv did it fast and cheap though to be honest would have preferred the secondary exterior box on the inside but the pre-attached cables were not long enough. As I have an electric metal door they couldn't use an earth rod so installed a box of tricks to deal with that somehow - no issue but it does buzz a bit.

They installed a new switch in the consumer unit, an adjacent metal box with an RCD in side, the black box to deal with earthing due to door, exterior interconnection box and the main charger connection wall box. Some pics below in case of any use. All took about 3 hours and should cost £300 - though the billing system was not working so no invoice yet ?

 

@Jeremy Harris FYI - this unit has no connection to house wifi so no capability for external interference. Well unless they have a 3/4G modem and SIM but I very much doubt that.

 

 

Note metal bar is in fact part of  a ladder

 

[Jeremy Harris]

42 minutes ago, Adam2 said:

So to continue the EV journey... buying used from Tesla is painful in the extreme, not enough people handling orders so 2 weeks after deposit paid only 1 email, no calls or emails answered and no delivery date of course. But, the price is great compared to alternatives so will have to be pleased with that for now

?

 

Buying from Tesla is painful, whether it's new or used.  The cars are incredible, but service from Tesla, especially communications, is simply appallingly bad.  You have to really want one of their cars to put up with the atrocious way they behave as a company.

 

42 minutes ago, Adam2 said:

On the charger front some great news - that is installed. ChargedEv did it fast and cheap though to be honest would have preferred the secondary exterior box on the inside but the pre-attached cables were not long enough. As I have an electric metal door they couldn't use an earth rod so installed a box of tricks to deal with that somehow - no issue but it does buzz a bit.

They installed a new switch in the consumer unit, an adjacent metal box with an RCD in side, the black box to deal with earthing due to door, exterior interconnection box and the main charger connection wall box. Some pics below in case of any use. All took about 3 hours and should cost £300 - though the billing system was not working so no invoice yet?

 

 

The box you have is almost certainly one of these units: https://matt-e.co.uk/wp-content/uploads/2019/10/SP-EVCP-Installation-Manual-v1.2-Oct-2019-A5-QCode.pdf  or something similar.  Questionable as to whether it really complies with Section 722 of BS7671:2018, but they do seem to be selling them as a compliant solution (hard to see how just monitoring L and N can comply, but no doubt they've managed to persuade someone within the IET).

 

 

42 minutes ago, Adam2 said:

 

@Jeremy Harris FYI - this unit has no connection to house wifi so no capability for external interference. Well unless they have a 3/4G modem and SIM but I very much doubt that.

 

 

The charge point does have an internal SIM card and LTE connection, to allow the mandatory control required by OLEV, to allow grid balancing etc.

[ProDave]

8 minutes ago, Jeremy Harris said:

 

The box you have is almost certainly one of these units: https://matt-e.co.uk/wp-content/uploads/2019/10/SP-EVCP-Installation-Manual-v1.2-Oct-2019-A5-QCode.pdf  or something similar.  Questionable as to whether it really complies with Section 722 of BS7671:2018, but they do seem to be selling them as a compliant solution (hard to see how just monitoring L and N can comply, but no doubt they've managed to persuade someone within the IET).

 

The usual fault with PME is a break in the PEN conductor, allowing the PME earth to rise almost to L potential.  A better check would seem to be use a rod, just as a reference, and trip if the PME earth differs from local earth by a set amount (a bit like the old voltage operated earth leakage devices)

 

I guess it might be doing a loop impedance test, which should also detect that condition?

[Jeremy Harris]

45 minutes ago, ProDave said:

The usual fault with PME is a break in the PEN conductor, allowing the PME earth to rise almost to L potential.  A better check would seem to be use a rod, just as a reference, and trip if the PME earth differs from local earth by a set amount (a bit like the old voltage operated earth leakage devices)

 

I guess it might be doing a loop impedance test, which should also detect that condition?

 

 

That's exactly the scenario that the three protective options in Section 722 are intended to address.  The unit I linked to has a contactor that disconnects L, N and PE  when it detects a voltage change on the incoming L and N, making the assumption that a broken PEN will change the voltage between L & N.  The reason for breaking all three conductors is to prevent the touch voltage on the car body (which will be at the potential of the PE connection) from rising above a safe limit relative to the local earth next to the car, where someone may be standing.

 

The difficult case is where there is another bit of earthed metal within touching distance, like an electric door, or maybe a freezer inside a garage where a car is charged.  You then have a problem where a PEN fault could result in there being a dangerous PD between the car body and another bit of metal connected to a different earth.

 

The whole thing is made more complicated because the signalling system used by the charge point comms system puts up to ~ 6 mA of DC down the car CPC, and that's enough to blind a Type AC or Type A RCD/RCBO, preventing it from tripping in the event of an AC leakage.

 

The fix I've used is to use a Type A RCBO (OK for AC and pulsed DC) plus a  DC sensing leakage detector (one of these: http://www.stegen.com/en/ev-products/126-residual-current-sensor.html ) to disable the charge point.  Not 100% compliant, though, as it will reset if the power goes off and on again.  The expensive way to do it is to use a Type B RCD/RCBO and earth electrode, but that may need changing the earth arrangements for other nearby parts of the installation to TT, through the same RCD/RCBO, in order to get around any problem with being able to touch two differently earthed bits of metal.

[Adam2]

2 hours ago, Jeremy Harris said:

The charge point does have an internal SIM card and LTE connection, to allow the mandatory control required by OLEV, to allow grid balancing etc.

Ah yes can see that is an option. All I can find on digging into this is that past customers have had letters saying that they needed to start paying if they wanted to keep access to the app/data - sounds more like none is paying the SIM bills anymore ? Not sure how to tell if this is actually installed without opening it up, though for current location not so concerned.

 

[Jeremy Harris]

1 minute ago, Adam2 said:

Ah yes can see that is an option. All I can find on digging into this is that past customers have had letters saying that they needed to start paying if they wanted to keep access to the app/data - sounds more like none is paying the SIM bills anymore ? Not sure how to tell if this is actually installed without opening it up, though for current location not so concerned.

 

 

 

If it was installed with an OLEV grant, then it's mandatory that the smart connectivity be fitted and working.  If it was fitted without an OLEV grant, then no need for the smart connectivity, and arguably it will be a LOT better without it.  On one of the Tesla forums there are many reports of flaky smart charge points, badly designed apps, unreliability, etc.  Having read many of these I started a thread asking whether Tesla owners (who, as a subset of people, probably lean towards anything with a bit of tech in it) and the results were overwhelmingly in favour of dumb charge points:  https://teslamotorsclub.com/tmc/threads/are-smart-charge-points-worth-having.177611/

[Adam2]

Yes, seems they're the rules but there is suspicion that installers aren't exactly following the rules. Will see when I can work out how to find a Bp chargemaster app on android - instaleld one and it was just for the bloody petrol station payments! 

 

Interesting thread on Tesla forum - they have too many tempting after-market mods, much too distracting from my house build.....