DIY domestic electric vehicle charging point?

[Tim+]

Doable? Worth doing?

In Scotland I see that there are grants available for professional installations (which seem to be around the £1000 mark).

Are there significant savings to be had by DIYing it and are there any significant ?gotchas? that one needs to be aware of? I do realise that this probably falls into the ?if you have to ask, you shouldn?t be doing it? category of jobs but just curious to know if a) you averagely competent DIYer could do it or b) make some saving by installing an appropriate unconnected cable for a sparky to finish off?

Tim

[nothanks]

I explored this a few years ago and found lots of info on-line but decided to save the hassle so bought (and modified) a Rolec charge point ... there are several on fleabay at the moment.

[spuorgelgoog]

- Your main supply may be inadequate especially if you already have electri c heating or other high loads on a 40A or 60A supply. You might be able to have a fuse upgrade without a new service cable.

- There are specific rules about earthing for electric vehicle charge point s and you may need a new earth rod installation. Earth rod testing is not a simple matter if you do the job properly - I suspect that most installers don't.

- For cheapest charging you may want a special tariff, which may need a met er change and a separate or dual-tariff consumer unit.

Owain

[John Rumm]

FTAOD, are we talking just installing a off the shelf charging unit, or are you suggesting building a complete charger from the component level up?

Yup, and only if doing the former!

ISTR there were some for England as well.

Much the same as any outdoor wiring project, with the possible additional requirement of needing a type A RCD for protection. The latest amendment to BS7671 has a bit more on vehicle charging.

(we probably ought to stick something in the wiki)

I rarely subscribe to that train of logic! Its seems far more sensible to find out what you need to know before doing the job.

(that I get mildly narked by people telling me "its too difficult for you, leave it to the pros!")

Either would be ok, although you would probably need to confirm with the fitter if doing the latter - they may not be as keen if they did not have full control over the job.

[Peter Johnson]

Hearing intermittant drilling outside this morning, I went to out to see what was going on, and found electricians installing a charger for the neighbour's new electric Kia. Reading this thread I went out to see if it was all in his garage or if it had an external connection. It's all inside, it's a smart one that cost him £600 installed. As his power supply is still 40A he has been warned about using other high-drain devices at the same time but is going to get it upgraded to

80A.

[Tim+]

Off the shelf. ;-)

Thanks for that John. I?ve checked my main fuse and it?s got 100A on it so I think I?m okay from the supply side of things. We don?t use our supply for much other than normal domestic appliances and a underfloor heating in a bathroom so I don?t think we?ll struggle on that score.

Thinking about positioning, I suspect the most useful place will be outside rather than in our garage (which was my first thought). The cable run would probably have to be under-floor where access is very limited and there wouldn?t really any option to fix the cable to anything. Is this allowable? I guess it?ll have to be some sort of armoured cable.

Our earthing system seems to be a wide metal braided strap attached to the incoming mains cable. (Looks like a lead sheath on the incomer.). Is this okay?

Lastly, chargers seem to have varying levels of ?smarts? built in. Are these just gimmicks or does it depend on the car? I believe on some cars charging intervals can be programmed into the car rather than into the charging box. This is all new to me as you may have guessed. ;-)

Incidentally, for anyone who hasn?t tried driving a car in ?one pedal mode? whereby braking progressively increases as you lift off the throttle, I found it incredibly straightforward to get used to and found it really useful in town traffic during my test drive today.

Tim

[Andy Burns]

You need to read the regs on car charging and earthing (see John Ward's youtube videos) unless you have a very fancy charger that can detach the earth in fault conditions, you probably need a separate earth rod for the car and not to connect it to you main earth.

[harry]

o realise that

??t be doing

Unless you are a travelling salesman, you don't need one. A slow charger off a 13a plug will be fine overnight. Every Kwh takes you about four miles. So, a 13a/3Kw socket gives you 12 miles of range for every hour plugged in.

eg. Ten hours plugged in overnight therefore gives 120 miles of range.

Numbers may vary with other cars but this gives the ballpark figures.

[harry]

got 100A on it so

use our supply

built in. Are

?one pedal mode?

The charger has to limit the current delivered and shut down automatically when the battery is charged.

[Andy Burns]

Generally the EVSE (box on the wall) limits the current, and the charger (built into the car) stops when the battery is full.

[Tim+]

Thanks for the info. I think it?s looking more like a ?get a man in? job for me anyway. ;-)

Not in the Honda E. Reviews suggested that it can be a bit ?harsh? in the Honda and apart from ON/OFF, it?s not adjustable. The salesman suggested that we *shouldn?t* try it which was obviously either reverse psychology or a red rag to a bull. Of course I HAD to try it. ;-)

Anyhow, despite it being my first ever experience of one pedal mode I loved it. Felt like ?the future?. Probably wouldn?t use it much on the open road but in town it was great.

Which is what the Honda felt like with the one pedal mode off.

Tim

[Tim+]

I?ve read that the 13A lead only charge at about 10A as the load is continuous and your average 13A socket isn?t entirely happy providing that amount of power for any length of time.

Tim

[Theo]

Just so you know, these are the kind of thing the installer needs to consider:

(long but worth watching to the end)

Interesting how he points out something that looks like TN-S might turn into TN-C-S as a result of works in the street or further away.

If it were me I'd get a man in...

Apparently there are paddles on the steering wheel to select three modes of regen (p398-403):

I think it can be useful to tweak because for town you can use fairly aggressive regen, while on the motorway you want something a bit more gentle.

Looks like an interesting car :)

Theo

[Andrew]

"Excessive heat can damage the battery. On hot sunny days, avoid leaving the car in direct sunlight". Hmmm. Tricky, even in Southern England, never mind Southern Europe.

[ARW]

I did the car charging course and should know the answer but I have only fitted one charging point in 2 years and I need to refresh my memory by reading the literature I was given on the course again.

ISTR that the grants only apply if you are buying an electric car and not in preparation for buying one in the future.

Car charging points are supposed to be notified to OLEV so that a record can be kept for when the national grid is about to fail and the smart meters can turn them off [1]

It will probably need a TT supply.

[1] That comment was from the tutor.

[tabbypurr]

do realise that

I assume it's so you can be heavily taxed later.

NT

[Roger Hayter]

So he didn't go for the whimsical idea that they could reverse the direction of power delivery?

[Andrew]

can a Smart Meter just turn of the car charger, or does everthing go off ?.

[ARW]

It was mentioned....

[ARW]

ATM everything.

I do expect that to change and so did the tutor.