Rebel44 wrote:Bigger battery allow EV to become more (or even all) driving to be done in EV - eliminating more feul usage by ICE. Over the lifetime of EV it would more than compansate extra cost - both carbon emisions and $$$.
You're talking there about a 'fleet' lifetime CO2, that is, how different populations of car users ('urban' or 'long distance') use their vehicles.
I agree you have a point, but only where the battery capacity of the pack is being used optimally. If you are talking about having EVs where less than 30% of the battery is being used for the majority of days then, no, the fleet CO2 would be higher. So if one user needs 50 miles a day for 95% of his days and has a Leaf, and another uses 150 miles a day and has a Model S, I'd tend to agree there is more to consider there. But if the 50 mile user had a 85kWh Model S and barely exercised the battery, then his CO2 lifetime emissions would be higher than if he had an ICE - though then there is a secondary argument that by using the battery very little he might then get double the lifetime out of it and if it achieves 20 year lifetime then it might beat ICE.
So I do see merit in your point, but it goes to show that larger battery size options should indeed be 'options'. It would help, perhaps it should be compulsory, that the carbon footprint of vehicle manufacture should be quoted too, along with the mileage. In a way, it makes no sense to declare CO2 for use but not for manufacture. I guess we'll see it required, eventually. You can access some manufacturers' environmental impact reports on their models, but it is few and inconsistent between makers, even models with a maker.