Posted 2 October 2023
Electric Vehicle charging - help me with the maths
Hello.
A major car hire firm has a great price for a Polestar 2 for a weekend hire.
I need to understand what the electricity will cost me.
Journey - approx 300 miles, of which around 250 miles will be on motorways and the rest on A roads.
Probably driving at speed limit.
Will charge it at home through 3 pin plug overnight (lets say 10 hours) before going to a rapid charger nearby in the morning and returning it.
The rapid charger costs £0.75p kWh
Happy to hear a ballpark figure.
I won't be charging it anywhere other than at rapid chargers costing £0.75p kWH and 10 hours at home on 3 pin the night before returning.
Thanks.
A major car hire firm has a great price for a Polestar 2 for a weekend hire.
I need to understand what the electricity will cost me.
Journey - approx 300 miles, of which around 250 miles will be on motorways and the rest on A roads.
Probably driving at speed limit.
Will charge it at home through 3 pin plug overnight (lets say 10 hours) before going to a rapid charger nearby in the morning and returning it.
The rapid charger costs £0.75p kWh
Happy to hear a ballpark figure.
I won't be charging it anywhere other than at rapid chargers costing £0.75p kWH and 10 hours at home on 3 pin the night before returning.
Thanks.
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19 Comments
sorted byPrice has dropped to £70 for a 2 day weekend hire, which sounds incredible.
Even if charging entirely at rapid chargers for 75p (Instavolt) or 79p (BP Pulse) the overall cost (hire + fuel) won't be noticeably more expensive than a mid sized ICE car hire (hire fee is about £25 more), and will definitely be a better driving experience.
The car hire place confirmed they don't supply 3 pin cables, so I am restricted to public chargers.
I will need to charge it twice - once near my destination on day 1, and once enroute to the car rental place in the morning of day 3.
Thanks for the useful info everyone.
As I mentioned in an earlier comment, if you are on the motorways and highways it's mostly going to be Gridserve Electric Highway and Ionity that are the two networks you'll see a lot of. Gridserve is slightly cheaper at 69p and are generally very reliable now they have the new chargers installed everywhere. Instavolt who you mention are pretty good too, just a lot of their chargers are slower ones than the two networks above.
Two handy apps to install on your phone ahead of your journey are Zap Map - To help find chargers and check their availability. And also ABRP - This is a shockingly accurate route planner that will know exactly how far you can travel on your journey, where is best to plug in to charge, how long you will need to charge for etc.
10hrs on a granny charger will give you 27kwh give or take. Assuming its standard rate at 27p, that's £7.29
Assuming the rest is at 75p then another 58kwh. That's £43.50.
£50 give or take.
Question is, if the Polestar will do 300miles with however much charge it comes with.
At that point with standard electric and expensive public charging, it's not any cheaper than a diesel.
By comparison the same 300 miles in mine would be at around 4.5miles/kwh (66kwh) and on a 7kw charger at home I could get 6hrs at 7.5p. 42kwh = £3.15. Then the rest at a Tesla supercharger at 34p. 24kwh = £8.16.
Total cost of £11.31.
The two figures kind of highlights the differences between home charging on 3 pin and a dedicated charger with off peak tariff as well as "public" vs Tesla supercharger prices. £40 is a lot of money difference.
Assuming about 300 miles of mostly highway driving, in a standard range Polestar 2, you should use about 100kWh of energy to drive that journey itself.
If exclusively using a rapid charger at 75p/kWh you would be looking at £75. - And I would encourage you to do this even if you do get given a 3-pin cable. You don't want to be charging overnight for the first time and finding your home's elecrrics aren't up to a sustained heavy load and starts a fire while you sleep. It's going to be slow to charge anyway, and the battery will be colder the next morning meaning finishing it off at a rapid charger will take longer than charging a warm battery pack.
Motorway service station chargers operated by Gridserve's Electric Highway - The main operator across the UK motorway network is 69p per kWh which should be a little cheaper, and a little more convenient than whatever network you had in mind at 75p.
It's 2.4kw.
It's not a heavy load.
Also, this is a (probably) newish Polestar 2. I'm not leaving that overnight in a deserted carpark.
Besides, I've only got it for 2 nights and won't have time to charge extensively anywhere.
Thanks anyway.
My quick maths suggested about £70 in electricity charges, so I'm glad to see I wasn't too far off.
If I instead go for a petrol mid-sized car, I calculate petrol at a regular petrol station will cost me perhaps £40 - £50, with none of the range anxiety or twiddling my thumbs at a public rapid charger.
Oddly, the Polestar is about £72 to hire for a weekend, and the mid-sized car is about £20 more.
The Polestar is clearly a more impressive and comfortable vehicle out of the two but it doesn't look like a clear winner here.
What would you do?
75p is ludicrous.
If you have to charge in public an EV is not a cheap vehicle to operate.