22KW charger questions + getting 3 phase installed?


Well-known Member
Having filled out a few forms online and surveyed my home, which is a pretty standard installation, and having received no call backs, I'm guessing I've missed the EV grant (see here Is it too late to get OLEV home charger?).

I've been struggling with which home charger to go for. I finally managed to get the Mrs to show some interest and it appears the Anderson A2 is the one, which I note can also be had in 22kW

Given that I'm not going to get the grant I have a bit of time available. This led me to wonder if trying to get the 22kW version would be a good idea. We have a Renault Zoe coming and I believe it can rapid charge, so a 22kW charger won't be wasted. I have a PHEV running off a granny charger and already wish it would charge faster. I know a 7kW will charge it at something like 3.6kW vs 2kW. which will be an improvement, but I don't to have the same issues with the Zoe, wishing it would charge faster.

We are also going to get our driveway widened, so before that I'm wondering if paying to go up to 3 phase is an option.

Has anyone done this or got any idea what is involved and the possible costs?


Distinguished Member
You can get a free quote from your local electricity distributor (not your current supplier - unless they are the same) for conversion to 3 phase. Somebody from the distributor will have to come out to assess how much digging etc is required to get the new cable into your house and terminate etc. but I would expect it to be relatively expensive as at least £1000 if not a few k. One quick google search was in the 20k range as there was no 3 phase supply in the street :(

I had my cutout upgraded to 100A recently and was talking to them about 3 phase upgrade, the guy was more worried that the local substation would struggle to feed more houses upgrading on the single-phase let alone if they jumped to 3 phase. :D


Distinguished Member
I'm not sure of the costs, but I imagine quite a bit more pricey tbh. Doing a Google found a forum where someone paid ~£4k to have existing 1 phase removed and 3 phase installed as the local supply had capacity and was not too far from their property. I presume he would also then need to have some fuse board work done as I presume at that point you have 3 supply wires not just 1 and you probably need your fuse board configured such that some devices are on #1, #2 & #3 phase etc if you go that far..

If it’s solely for the car charger then the thing you may want to weigh up is how many miles per day you will be doing and how long a time window you will typically have to charge the car when back at home.

The Zoe I think has a 52kwh battery, so if it's on say only 10% when you get back each day as you drive 175+ miles per day, then that will take ~6.6 hours to charge overnight on 7hw which shouldn’t be an issue but if it is then it will charge in ~2.1 hours on 22kw.

If you really only have 2-3 hours available to charge and you do 175+ mile per day then it may be worth the extra cost. If you only do 30 miles per day then even with just a 7kw that'll only take ~1hr to charge each day. Even on a 3 pin granny charger at 2.3kw that’s only ~3.5 hours.

You probably also need to consider that in general the faster you charge a battery the more strain you put on it and this may cause faster battery degradation. It's not always a massive issue these days with batteries that have heat management, i.e. they cool themselves to prevent them getting too hot during charging and so vastly reducing the degradation effect, but if I could charge enough at a slow rate, then there's little need to charge faster at the risk of the battery not having as long an overall life.

The majority of people in the UK only ever have 7kw at home (3ph is more popular in Europe) which is why many UK EVs are configured as 7-11kw on AC (type2 / round plug) and we spend the money configuring the faster 50-125kw+ DC charging capability (CCS / figure of 8 plug) which is what you tend to see when out and about.

The Zoe having a 22kw AC charger in the UK is pretty unique to the Zoe and unusual in the UK and maybe a hangover from when it did not use to have a fast DC charger of more modern EVs and so could be charged at a half decent speed on AC out and about and maybe also has something to do with it being a popular Euro car. If you ever changed later from a Zoe to another car (even Megane-E) you will probably not find anything faster than the usual 7/11kw AC.


Well-known Member
As the Zoe tends to be more of a town and city car with a lower range I’d suggest the cost of install will downgrade the value of owning the car and provide little real benefit unless you regularly return home nearly empty and need to be full soon after.


Distinguished Member
I had to have my supply checked when I fitted a heat pump for the house back in 2008/9

EDF (the network people at the time) told me my house was "unrated" i.e. they had no idea but it would be rubbish :)
"??? has no agreed availability and would be under 40kVA."

I could have gone for a single phase 100A supply but going to 3 phase meant I had more flexibility in what heat pumps to install. The main cost was digging up the pavement on the other side of the road, traffic barriers and "moleing" the new cable under the road and into the house.
Actually connecting up the supply in the hole over the road was done "live" by two guys which was something to see!
In the end I needed 2 heat pumps so the supply was needed anyway.

I paid £90 extra for an inspection to get it done quickly which was discounted against the £2900 it cost. This was over 10 yrs ago so I'm sure it will be a lot more now.

I also had to have my meter replaced simultaneously which was organised by my own electricity provider for free and actually went OK. I had to pay my electrician to connect up the existing consumer unit to one phase and deal with the other phases going to the second CU and heat pumps elsewhere. That wasn't included in the cost above as it was part of the renovation.

When I was getting my EO installed I considered a 3 phase charger ... for about 10 minutes.
They're much more expensive. My plugin hybrid wouldn't see any advantage at all over a regular 7kW point.

I can't see any reason why I'd need +200 miles range in a hurry when I got home. I might need that on a long trip somewhere else, so I'd use a fast charger en-route. When I get back I'll be charging overnight and sleeping even if there's another drive tomorrow.

The only possible exceptions I can think of would be if you regularly need to charge more than one vehicle to full capacity every day. Even then I'd prefer to have 2 points and charge both on Economy 7 etc.
If you were bringing a vehicle in flat and another driver was taking it out again for another long drive very quickly you might want the fastest charge, unless you're planning on setting up a taxi firm that seems unlikely.


Well-known Member
Thanks all. I need to do some maths and some thinking. Our electricity went off last year resulting them digging up over the road to restore it. Direct neighbours weren't affected so I assume the street is 3 phase. It's a shame I couldn't have slipped them few quid to upgrade me then.

The zoe is a 2.5 year lease. I didn't realise 22kW charging was rare, so paying a significant amount to have 22kW charging may not be worth it if zoe replacement is only 11kW capable. Given I will go full ev at some point it seems like it would be better to have 2x 11kW than 1x 22kW. Is there a reason 11kW chargers aren't available? I'm guessing you would just get 2x 22kW which would run at 11kW.


Staff member
The zoe is a 2.5 year lease. I didn't realise 22kW charging was rare, so paying a significant amount to have 22kW charging may not be worth it if zoe replacement is only 11kW capable. Given I will go full ev at some point it seems like it would be better to have 2x 11kW than 1x 22kW. Is there a reason 11kW chargers aren't available?
Yes - sort of. Typically a single phase AC outlet will max out at ~7kW (not 11kW). A three-phase gets you 3x that = 21; 22 in practice). I'm no expert, but I suspect 11kW in one phase is rare or non-existent (whether due to some technical difficulty or otherwise); a single phase at 7kW appears to be the standard. 11kW (at max 7kW/phase) would need two phases which seems to be equally rare. You may actually need 3 phase (each at just shy of 4kW) to get 11. In which case you may as well get 22 in case it's of future use. A "lesser" car (if you find one) will simply limit the current it draws to what it can cope with. As will a 7kW car - it will use one phase only. Indeed, if you did manage to get 11kW in three phases, a future car with only one phase ability would be limited to ~4kW or would blow fuses.

But it brings me round to a question for you to ask yourself: is your usage pattern of the vehicle highly likely to either
(a) involve several separate trips from home and back which, during the course of any one single day exceeds the range of the car or exceeds ~250 miles (whichever is the lesser) round trip.
(b) totally preclude leaving the vehicle unattended for, say 10 hours (eg while you sleep etc.) ?

I'd suggest only if these either of these things is true are you going to benefit from going any higher than 7kW. 10 hours (eg overnight inc. watching TV and having breakfast, etc) at 7kW gives you a top up of 70kWh (well, a bit less allowing for system inefficiency) or to full if the car battery has less capacity - and at say 4 miles/kWh, that's enough for over 250 miles. Which kind of negates the need for it to happen more quickly, unless either of those above things are indeed likely.


In ten years time we may look back at our 7kW AC chargers and despair while our neighbours all have 50kW DC chargers working off whatever magic supply they require. I wouldn't try and future proof at a cost of thousands in case the future goes in a different direction.


Distinguished Member
I'm pinning my hope on better EVs not better home charging.
The whole grid infrastructure would need major upgrades to support that speed of charging at home and the benefits as discussed are not clear cut.
I hope that battery efficiency will mean we just need less input juice for the same range.
Faster charging away from home should mean we can fit smaller batteries in EVs - less weight to lug on most typical short journeys so better efficiency - but without the range anxiety and inconvenience of the slower charging, lower capacity vehicles available now.

Given the phase out of fossil fuels for home heating then the grid IS going to need major work just to support the heat pumps that replace them. Not sure how that is going to work if you can't buy a gas or oil boiler but the electricity network won't authorise a heat pump that's big enough for your house.

The heat pumps I have run day and night in the winter.
In the 141 days since I had my smart meter installed I used an average 68kWh per day peak 31kWh off peak per day - so 99kWh a day / 4kw an hour :eek:
(that's including all our other electricity usage inc the hybrid too but working that out means I need a little lie down :eek: )1

In contrast the most my EO has logged to charge my GTE was 7.26kWh over 3 hours - so a 2.42kW load. If I were charging a full EV I'd be going at twice the rate(ish) so a 5kW load for several hours.
Or a bit more than I'm drawing all the time to heat the house.

When I was looking for cables I came across this link.
Important Note About 11kW Cables: 11kW cables (3 Phase, 16A) are not usually ideal as a general charging cable in the UK. This is due to the fact that most EVSE (Charge points) in the UK are single-phase only. This would cause your 11kW cable to charge at 1 phase, 16A which is a 3.6kW charge rate, the slowest you can get! Most users would benefit more from a 7.2kW charging cable or the heavier 22kW charging cable.

So to make use of the 3 phase power cable anywhere else, you'd want to buy the heavier weight 22kW cable. My single phased 10m cable weighs 5Kg and wrangling it back onto the holder isn't trivial.
I wonder what tethered cables are supplied with 3 phase chargers - you'd be annoyed if it was a 11kW cable so your single phase vehicle charged at the speed of a granny charger(ish)

Returning to the original point - I would start with a single 7kW point unless you have another reason to pay several thousand to upgrade your house supply.


Short version - stick with basic 7kw charger....


Well-known Member
Thanks all. I've a had a quote of £1649 for the Andersen A2 with wooden front. I'm not sure how much less it would have been with the grant. There is no option for that anyway as they take 6 weeks to make. I'm just waiting on a couple more quotes.

My DNO did get back to me with form for my EV installer to complete, but as above I will give this a miss.


Well-known Member
My view is to see what kind of prices are quoted by your DNO for a 3-ph upgrade and then make your decision.

3-ph will give you lots of headroom going forward - as all-electric household Inwish I’d put in 3-ph when I built the house 15 years ago. I already have to use load management to run my
2 x 7kW EVSEs, and am stuck with a 3.68kW export limit on my solar panels (meaning I could only fit a 4kW array without spending time and money applying for a larger export limit).

I’d have a bit more flexibility to change how so deal with heating and hot water at home with 3-ph too, but for now that’s not too much of an issue - I’m sticking with my gshp for heating and hot water for now (would probably have moved to a heating-only heat pump and a Sunamp hot water system if I had some extra capacity).

And my latest EV is 11kW 3-ph compatible, so having a 3-ph charger would allow me to add 65% to my battery capacity in the 4 hour Octopus Go cheap tariff period rather than 40% I can manage just now.


Distinguished Member
I've a had a quote of £1649 for the Andersen A2 with wooden front. I'm not sure how much less it would have been with the grant.

The OZEV Home Charge grant was £350 if the device and your home qualified.
Jury is out on what new installs without it might be.

Looking at the charger it's a very nice looking unit :thumbsup:

I guess you could build a nice looking cabinet around anything if you wanted.
My EO mini Pro2 is the smallest I found but then having the cable dangling around it kind of offsets that minimal look :)

My advice would be to check that the tethered cable will be long enough - with a garden hose or whatever. I needed 10m but that does allow me some flexibility to park nose in or out.
The 6m VW cable is too short to do either. Reparking to get 6" closer to connect the granny charger was a PITA!

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