Electric car query - Do we need an ultra-fast home charger?

[Pipsquiggle]

My DH needs a new car, his current one is knackered.
We are considering going electric.
His car is mainly for his hour commute each way to work - circa 90 miles each day. Or local journeys.
We had an electrician out who informed us that the electricity supply to the garage can't support an ultra fast charger.
My DH is saying he now doesn't want an electric because we HAVE to have an ultra fast charger.
My question is do we really need an ultra fast electric charger at our home? - any examples of why an ultra fast charger is or isn't necessary would be great.
TIA

I think there's a bit of confusion in terminology

Ultra fast would refer to the kind of public chargers you get at fuel stations, services, some retail parks 50kwh-150kWh. You need expensive infrastructure to run them.

Home chargers are either 3 pin run off a normal socket, or 7kw dedicated charging unit in most cases. Either of those would give enough charge overnight for your use.

Okay 3-pin is okay if you are doing very low daily mileage. For example for my EV, it would take 20+ hours to charge from near empty to say 90% on the 3-pin. It is more of a pain though and your internal wiring has mto be good to run a constant 2.5kwh at 13amp for 8+ hours overnight. The Masterplug charger from Screwfix is good, I limited ours to 10amp for safety.

If there was no chance of getting a 7KwH charger I prob wouldn’t bother with the EV honestly as the granny charge is inconvenient and if you do longer journeys it’s not practical. As a stopgap it’s fine. We did it for six months and I was very glad to get our charger installed!

It's possible to do without home charging altogether but it's more inconvenient and also expensive because you end up paying for public charging more often. So it's worth getting this right, either by running the cable to the garage or by changing where you park your car.

If you do get a charger installed, consider whether you will ever have solar panels. If there is a chance you might get them in the future it's worth having a charger that can charge at either 2kW or 7kW because you will never have 7kW of excess solar you can put on the car but you will often have 2kW and the car can drink that up if it's parked there in a sunny day. Hypervolt is one example of a charger that does this.

With that kind of commute you realistically do need 7kW charger but you could manage with stopgap solutions for a few months if it took you a while to get the charger installed. Long term you'd need to get this sorted properly, with a charger at home or at the workplace (and workplace charging likely to be on a public tariff so much more expensive)

Our installers ran a cable under a path, along a trench across the grass, then through a stone wall to get to the driveway for the (zappi) 7kW charger. They had all the kit including massive drills etc. Obviously not mad cheap but we live rurally where lots of people have evs (not an especially well-off area either, but people do a lot of long commutes)..And so we reckon by the time we move, it will be considered something people would expect - or price to add in - to any house selling price just like double glazing or a second bathroom. And our mileage costs are now SO low.

Can't you park close to the house when you are charging and have the charger on the house wall?

There are two things to consider if you are going to rely on a granny charger, which plugs into a normal 3 pin socket.

The first is whether the overnight charge is going to be enough to cover your daily commute. For 90 miles, you will need to add 20-30kWh, depending on the efficiency of your car and the time of year (batteries are less efficient in cold weather, and rain and motorway speeds also make it less efficient). A typical granny charger runs at 2.2kW, but you lose about 10% through charging losses. So rule of thumb is you will add 2kWh per hour of charging, which means you will need to charge for 10-15 hours per night to keep up. However, bear in mind you don’t need to start each day at 100%, depending on your weekend usage you may be able to top up enough then. Or you could do an occasional public charge to make up the difference.

The other thing is whether the wiring in your house is sufficiently robust to withstand 2.2kW draw hour, after hour, after hour, every day, for year after year after year. The circuit will be rated at 13A, but it is not expected to do that continuously. Things may eventually overheat.

Presumably the supply to your garage could be upgraded to support a 7kW charger. Yes, it will cost extra. But with 450 miles a week regular commute, and a good EV tariff, you will save a fortune in fuel bills. 450 miles on an EV tariff, even with rise from the Iran war, will cost around £10-£15. How much will it cost in petrol or diesel?

We are absolutely fine with granny chargers that we had anyway. They charge about 3-4% an hour (we have a MG ZS). Typically overnight in the cheapest tariff (11:30pm to 5:30am) I’d get about 20%. If I need to do a bit more (say from 40% to 80%) I’d plug it in for 10 hours. I typically need to charge 20-30-40% overnight, rarely more.

I'm sure to be flamed for this, but I'm going to have to let pedantry get the better of me:

Power is measured in kW. (kiloWatts - 1000 Watts)
Domestic electrical energy is measured in kWh. 1 kWh is the amount of energy supplied by a 1kW power source running for 1 hour.

So chargers are rated by their power e.g. 7kW (NOT 7kWh)
Batteries are rated by the amount of energy they can store e.g. 60kWh

I remember we discussed an EV charger with the electrician/ builder as we had the socket installed when we converted the garage. We had a hybrid that we were returning as it was during Covid and WFH, so decided against when they quoted. The socket was much cheaper and multi-use. I think it is on a separate dedicated circuit, so this might make a difference.

It's perfectly adequate for our normal use, especially with the petrol as back up if going further than the 70m (I think) range. We also have another car.

I often drive 30m round trip in the morning, plug in and it's back to full when I use it again in the late afternoon. I don't bother though if only for a few hours as there is enough charge for the journey anyway. (I take my son to the train station for Uni and collect again.)

3-pin was sufficient for us (schools, shops, dog walking, occasional trip to London or Guildford), but it of course depends on your daily mileage. I’d say I do quite a bit if driving, the school is about 25 mins away for example. And yet the 3-pin charger is absolutely adequate. We had the same dilemma - do we get these fancy round ones, how much are they, omg! I don’t think ultrafast chargers (150 kW) can be installed in a private residence anyway. They are only just being rolled out on the motorways! Those are a pleasure of course, 30-40 mins from, I don’t know, 20% to 80%. (You rarely need to charge to 100% and it is not good for the battery).

@WhosGotTheKeysToMyBimma

Yes I freely admit I got this wrong in my OP.

Ultra fast = motorways / petrol stations
7KW = car charging point at home near the meter (this is what I thought was ultra fast in my OP)
3 pin plug point = very slow (this is what we could use currently on our garage)

The electrician has confused thing by referring to it as ultra fast
what he probably meant was the 7kw ones that are faster than 3 pin plugs

You may need an upgrade to the electric supply to your home. This is free and will be done by your local electricity network operator. For me in the East, it’s UK Power Networks.

The company fitting your charger will be able to advise. They will then run the cable from where the electricity enters your home to where you want the charger. It costs around £1000 to install.

If your husband is planning on driving 90 miles a day, he’ll need a car with a decent range. He won’t be able to charge one using a 3 pin plug.

Think of it as an investment in your home.

Ah, we had a similar issue and couldn't afford the digging up of the garden, but you can get extra long charging cables which reach from the house to where we park our car (ours is actually across our back garden, if anywhere publicly accessible you might have to make sure it's not creating a trip hazard)

We have a hybrid EV. We charge it via a normal outlet in the garage. We will eventually get a dedicated fast charger, but as it’s a lot of faff and expense, we are putting it off.

All my cabling is outside and attached to the wall along the base of the building under the sills of doors etc. You don’t notice it at all. It’s probably about 10m in length

Yes that’s my bad! I used to volunteer for an energy charity helping people with their energy bills so my phone automatically autocorrects to kWh when I try to write kW and I’m too lazy to go back and change it. I shall make the effort forthwith!

You can buy long charging cables. I have an awkward driveway setup and three electric cars. I have an 18 meter cable that can reach all the cars so we don’t need to keep shuffling them to charge. You could have the charger unit wherever suits best and just have a long enough cable to reach the garage.

There are several variables here. 3 pin and 7Kwh are both AC and the car has to convert this to DC to charge the battery, hence it is slower. Also, 7Kwh is pretty much the maximum of a domestic single phase (240v) supply.

Then you have 22Kwh (fast), 50Kwh (rapid), and 150Kwh (ultra fast) which are all DC and charge the battery without the car needing to convert anything. These will likely all require a 3 phase (400v) supply to be installed.

To add extra complications, not all cars are able to use all types of charging. I very nearly bought an electric van that could only cope with 7Kwh and would not charge at a sufficient speed for me to use it given its range limitation.

Also, ultra fast charging will degrade the battery more quickly, so that should be reserved for long distance and not general use.

Due to the national grid not having sufficient capacity to power the demand, many chargers allow your supplier to decide when the car is charged. This can be turned off, but you run the risk of plugging the car in at say 8pm, assuming it is charging, needing to use it at 9pm and finding out that the supplier decided unilaterally not to start charging until midnight.

Lastly, the best balance for speed of charge and longevity of the car batteries is a 22Kwh charger, assuming your car will accept it (this will involve a 3 phase install). Most do to my understanding, I just happened on a van that didn't (Renault Kangoo if anyone is interested).

I just use my charger cable and put it in a normal plug. It charges overnight and I get 80% charge.

whats the charger?

What’s the range of your car?

I think you'll be okay with a self charging hybrid if you're commuting regularly.

My DH bought it over a year ago, but it looks like the one from EV Extras. Approx 7-10 miles of range per hour.

"If your daily mileage is less than 85 miles this charger is perfect for your electric vehicle.

The EV Extras charger is rated at 10 Amp (UK law to protect domestic circuits against overload and fire risk) and delivers 2.3kW of charge.

The 10 amp charging rate translates in more real world language to approximately 1 mile of range for every 6-9 minutes of charging (around 7 to 10 miles of range added per hour of charge)* which adds 85 to 120 miles of range to any electric vehicle or plug in hybrid vehicle when placed on a 12 hour overnight charge."

If I were doing a round trip of 90 miles a day, I wouldn’t risk a charger that could deliver max 120 miles. Thats way too little contingency. My charger charges to 100% overnight which will give me around 380 miles.

Fine for a hybrid I guess