Mike, You dont need another Smart meter. If its a modern one then it doesnt matter. Same with the wall charger.
The tarriffs will not really matter either. Its not as if you are going to fully charge your EV every night, unless you are an Uber driver.
Octopus may very well have the lowest EV off peak charging, but that is a minor consideration, the variance
between suppliers will be marginal.
Your energy bills during the day will define your energy costs.
Your current setup with a year old smart meter is fine, and the wall charger when its fitted, will be fine.
It looks confusing, but its not really.
If your mileage is 200 miles\week, then its going to cost you around £4.50 to fill up. If its 400 miles its going to cost £9.00.
I passed an EV charger in the council parking lot. The rate was 15p\Kw\H So of you charge your EV up to
80% and its a 55KW battery say to 40KW , its going to cost 15X40 which is £6.00.
In reality the the Council charger is not going to put too much charge in your car, but it will be enough to give your car some moderate range.
EV charging at service stations – well its going to be more expensive, nothing new there…but sometimes it is necessary.
Yes, we all know about the rubbish public charging situation, bvroken chargers, yadda yadda yadda, but that is NOW…in 6 months or a year the charging network is going to improve exponentially. Petrol pumps on the other hand, will start to disappear as demand drops off the cliff and prices go through the roof.