I'm not an expert, but I believe you need 3 phase electrics to charge at home above 7kw. Most homes in the UK do not have this, so I would not consider it an issue as to which car to buy. If you have local 22kw AC public chargers then you can take advantage of the 11kw. I'm sure someone will be along to correct me in a minute if I am wrong! ?

 

The 11kW option is 3 phase, in the UK there are very few homes with 3 phase, its normally found in business premises.
Europe is different where 3 phase to the home is common but at a lower current per phase than in the UK - hence the option which would be useful in Europe.

Check zap map for 11 and 22kW chargers near you, these are often rare as few cars in the UK can charge on 3 phase.

Given the above 3 phase charging is not that useful in the UK and unless your house is already fitted with 3 phase not worth considering.
Go for the 7.2Kw unit, its sufficient for overnight charging.

 

You will only be able to get a charger of >7kW at home if you have a three phase supply. Not many do, and upgrading is very expensive.

Having the 11kW charger will only give you a benefit if you charge at local AC chargers at either 11kW or 22kW. These are not rare, but not as common as 7kW. The real world benefit of having 11kW peak compared to 7kW peaked is pretty small. Getting the max speed depends on optimal battery temperatures and low state of charge. I suspect you will seek out CCS rapid charging more often if you have a low state of charge!

 

The latest i3 has the ability to charge from 3-phase 22kW posts at a rate of 11kWs maximum. For public charging on 3 phase posts (Ecotricity has some on free vend), you need a 3-phase cable. The 'good news' is that this cable will also work on any 3.6 or 7.2kW charging post.

I have a 7kW single phase tethered charger at home, and I use a 3-phase charging cable when away from home. CCS has its own cable.

 

Think about how long it takes to charge at both rates.
you will have a 4kwh differential between both. Considering the advised 20% min charge before plugging your your car this means you would be charging 40kw. so at 7kw this means just under 6 hours while on 11kw you will have just over 3.5 hours.
I'm not considering for this exercise the fact that from 85%(ish) you won't have a significant difference between the 2. This because charging rate will decrease as it approaches 100% so once the 11kw goes below 7kw there is no difference.
The question you need to ask is, do you need the 2.5 hours saving? Keep in mind that actually it will be more like 2 hours because of what I said above.
The 11kw only makes sense if:
- You will spend less than 6 hours at home overnight or you need to charge during the day.
- You sign up for eco7 meter and the period is below 6 hours and you will ALWAYS have less than 20% remaining and will ALWAYS charge to 100%.

 

The 11kw only makes sense if:

• You will spend less than 6 hours at home overnight or you need to charge during the day.
• You sign up for eco7 meter and the period is below 6 hours and you will ALWAYS have less than 20% remaining and will ALWAYS charge to 100%.

And you have to have 3 phase at home to get the 11kW, if not the car charges at 7.2kW anyway on single phase.

Costs 3-5 thousand
see here 3 phase upgrade

 

thinking about it, If I had to shell out to have 3 phase I'd probably go for a low power CCS (22kW) unit like this. CCS 22kW unit

 

Serously? at 19,000-odd Euros :

Mobiler DC Schnelllader MDC22 von Designwerk

Mobiler DC Schnelllader MDC22 von Designwerk

www.schnellladen.de

There are some small CCS units on Aliexpress at around £4K

 

One thing that worries me slightly is the dealers, Just how many folks will be sold the option after being told they can charge quicker at home by a salesman and then find out its just not so! This could lead to a number mis-selling claims.

The problem with the option is it's a cost unlike things like the I3 where the cars are sold with 3 phase but can charge at 7.2kW on single phase.

 

The other downside might be whether the 11kW car can actually charge at 7kW on a single phase supply... There's a small but non-zero chance that it might only make 3.6kW (16A) on a single phase supply.

 

I can see the technical reason why this might be the case ( 16A per phase, issues fusing 32A single vs. 16A 3-phase), but not being able to do 7kW on single phase would be a huge downside - are there any cars that actually have this limit?

 

It seems all 11kW cars parallel two of the 3.6kW chargers when on single phase. The corsa/pug specs suggest this is the case here as well with the 3 phase option.

 

The theory is that it was always intended for the car to use the Superchargers, but Daimler couldn’t agree on the terms for accessing the network.