Do you need a 7kw charger?
Discussion
Looking to swap out one of our ICE cars with an EV soon, been looking into battery range/charging etc to narrow down some candidates. While looking I was considering the 7kw charger install vs just using a granny charger and didn't think we'd actually need a faster rate than 3 pin (at least initially).
Anyway I made a quick tool to compare costs of both based on daily usage to see if the install would pay off over time. For me at least I can cover my usage with 3 pin. I shared on reddit last week and was popular so thought I'd share here in case anyone finds it useful in the future.
https://pcpfinancecalculator.co.uk/ev-charger-payb...
Anyway I made a quick tool to compare costs of both based on daily usage to see if the install would pay off over time. For me at least I can cover my usage with 3 pin. I shared on reddit last week and was popular so thought I'd share here in case anyone finds it useful in the future.
https://pcpfinancecalculator.co.uk/ev-charger-payb...
I think if you're planning to stay with EV's for more than a year or so, then a 7kw charger is worth it - even with a small mileage.
These days I do a much smaller mileage, however it's useful to be able to charge the car relatively quickly and to know that it's always sitting there charged up.
These days I do a much smaller mileage, however it's useful to be able to charge the car relatively quickly and to know that it's always sitting there charged up.
Two things wrong with that calculator - an EVSE shouldn't cost £1200 to install and currently you are not going to get a 7p / 27p off-peak / peak tariff as a new customer.
With current EV tariffs and doing the low (2,600) miles a year you will be doing you also need to do the maths on whether it would be cheaper to simply stay on a standard electricity tariff and pay the 25p rate to fuel it.
With current EV tariffs and doing the low (2,600) miles a year you will be doing you also need to do the maths on whether it would be cheaper to simply stay on a standard electricity tariff and pay the 25p rate to fuel it.
slievenashaska said:
Two things wrong with that calculator - an EVSE shouldn't cost £1200 to install and currently you are not going to get a 7p / 27p off-peak / peak tariff as a new customer.
With current EV tariffs and doing the low (2,600) miles a year you will be doing you also need to do the maths on whether it would be cheaper to simply stay on a standard electricity tariff and pay the 25p rate to fuel it.
It's a calculator not a statement of facts - you enter the install cost and unit rates which apply to you.With current EV tariffs and doing the low (2,600) miles a year you will be doing you also need to do the maths on whether it would be cheaper to simply stay on a standard electricity tariff and pay the 25p rate to fuel it.
NDA said:
I think if you're planning to stay with EV's for more than a year or so, then a 7kw charger is worth it - even with a small mileage.
These days I do a much smaller mileage, however it's useful to be able to charge the car relatively quickly and to know that it's always sitting there charged up.
Yes this is what I'm thinking now, even more so when we move both to EV. It was mainly whilst reading up on EVs in general I saw lots of posts were people are worrying about either getting a charger installed on day 1 of getting the car or somhow thinking unless every watt of charge wasn't from off peak rate it was a disaster. I'll be just using 3 pin for a while to see how it goes then look into chargers later.These days I do a much smaller mileage, however it's useful to be able to charge the car relatively quickly and to know that it's always sitting there charged up.
croyde said:
Slightly OT but why do electricity companies offer 7p off peak rates if you are charging a car but not if you don't want to freeze in the winter?
It's away of attracting good customer who consume relatively large amounts of electricity and pay their bills on time, rather than customers struggling to pay bills and constantly being in arrears.This is just another example of ignoring the devil in the details and assuming that what works for one person automatically is the answer for everyone. Details matter and everyone is different.
For example it assumes that there is a handy 3 pin socket capable of delivering the load for hour after hour every day. Thus installation cost is zero vs cost of 7kw charger. In the situation where installation and modification is needed to provide a suitable 3 pin supply then the calculation changes.
For example it assumes that there is a handy 3 pin socket capable of delivering the load for hour after hour every day. Thus installation cost is zero vs cost of 7kw charger. In the situation where installation and modification is needed to provide a suitable 3 pin supply then the calculation changes.
7Kw charger gives you flexibility.
You don't need to have it plugged in as long, so if you forget one evening and then wake up. You know you'll be charged up by the morning.
3pin is fine if you really don't want to commit or if you do local miles (5 miles a day or something).
I started with a 3pin but got a charger after 3 months. Worth it for me as I do a lot of miles.
You don't need to have it plugged in as long, so if you forget one evening and then wake up. You know you'll be charged up by the morning.
3pin is fine if you really don't want to commit or if you do local miles (5 miles a day or something).
I started with a 3pin but got a charger after 3 months. Worth it for me as I do a lot of miles.
ashenfie said:
croyde said:
Slightly OT but why do electricity companies offer 7p off peak rates if you are charging a car but not if you don't want to freeze in the winter?
It's away of attracting good customer who consume relatively large amounts of electricity and pay their bills on time, rather than customers struggling to pay bills and constantly being in arrears.
I’d fit the 7kw. Will give you more flexibility.
Ever used a quick charger vs slow one for one of your electronic devices? When you need it, you need it.
If you granny charge, I’d at least change the socket to something designed for EV charging and make sure the cabling is up to scratch. Saw quite a few youtubers who’s sockets slowly burned out when granny charging long term.
Ever used a quick charger vs slow one for one of your electronic devices? When you need it, you need it.
If you granny charge, I’d at least change the socket to something designed for EV charging and make sure the cabling is up to scratch. Saw quite a few youtubers who’s sockets slowly burned out when granny charging long term.
SWoll said:
Very few EV's are going to average 4 miles/kWh across an entire year, we didn't even see that in an i3. 3-3.5 miles/kWh far more realistic for most IME.
Granny chargers are also more susceptible to charging losses than a 7kW charger.
Any modern M3 or MY Tesla’s are efficient though. Generally 4 miles/kwh in winter and nearer 5 in summer, unless you spend your days cruising at 80+mph… Granny chargers are also more susceptible to charging losses than a 7kW charger.
croyde said:
Slightly OT but why do electricity companies offer 7p off peak rates if you are charging a car but not if you don't want to freeze in the winter?
The cheap overnight rate applies to everything in your home, not just charging a car.And the overnight electricity is cheap because of supply and demand.
T_S_M said:
A 7kw charger can be fitted for £600-700 (new charger and fitting), no need to pay over £1000 for one.
It's handy to have one if you don't have many miles left and need the car first thing in the morning.
Please can you share a link for any companies who can install a 7kw charger for this price? That's way cheaper than I've been able to find.It's handy to have one if you don't have many miles left and need the car first thing in the morning.
Phateuk said:
It's a calculator not a statement of facts - you enter the install cost and unit rates which apply to you.
Fair enough if you are stating it as a fact and it would cost you £1200 for a charger and you can get 7/27p a tariff, although I would like to know where you can get that tariff.ashenfie said:
croyde said:
Slightly OT but why do electricity companies offer 7p off peak rates if you are charging a car but not if you don't want to freeze in the winter?
It's away of attracting good customer who consume relatively large amounts of electricity and pay their bills on time, rather than customers struggling to pay bills and constantly being in arrears.E7 customers have 'dumb' demand for that overnight electricity where the storage heaters just click on at the off-peak time, but EV customers now have to have 'smart' EVSEs which the energy company can turn on or off as they desire to manage the demand.
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