Earlier quoted context omitted.
Nope. It isn’t that much energy compared to losses in ICE engines/existing inefficiencies. Feel free to do the energy calcs - there is no engineering challenge here for EVs that is currently unsolved.
I prefer practical tests. Right now, however, the authorities here encourage people to avoid using electric pre-heaters in order to save electricity, so I'll take your word for it. :) Ideally, things like this wouldn't be a problem, but where I live EV's is simply not an option during winter. Charging from a regular 240V/16A outlet takes too long, the nearest proper charging station is over 25km away, and the grid ou…
Assuming Cp = 0.32 kJ/kg•K, which seems about right, you’re talking about 3kwh to heat up a 75kwh sized pack from -25C (-13f) to 25C (77f), or about 4% of the pack capacity. Which about lines up with my experience ‘warming up’ ICE vehicles. It’s not great fuel economy wise to do so.
If you have a block heater, seems like those can be as much as 750-1500 watts. If a diesel, that block needs to get pretty warm, and it’s not like a ton+ of steel/cast iron doesn’t take a lot of energy to heat up either. And that’s ignoring transmission heaters, battery heaters, etc.
Is it 3kwh worth? That would depend on a lot of factors not specified, but it wouldn’t surprise me if it was close.
A 240V/16A outlet (16A is a bit unusual? Usually it’s multiples of 5), is 3.8KW Peak.
That would indeed be limiting, as assuming something like 90% efficiency a full charge is 20+ hours.
It’s an odd number to pick though, as unless someone has a very undersized utility feed, more shouldn’t be a big deal?
I know, some places have only a 50 amp panel and blow fuses anyway, but compared to buying a new car that’s a cheap problem to fix. Even a not shitty welder is going to want 240v/20A, and an old 50 amp panel can barely handle a space heater and other usage.
A typical electric stove is 240v/30A (or more) same with an electric dryer or AC.
If using a typical electric dryer type connection, that’s 7200 watts, and at 90% efficiency could recharge a fully discharged 75kwh pack in 11 hrs, which is ‘overnight’ in most situations.
Most newish residential construction has 150 or 200 amp, 240v split phase service and panels, or 36-48kw, which provides a lot of headroom.
Of course to your point, out in the sticks things are different, and I don’t know your situation or the local counties power infrastructure.
Just supply chain issues would be a show stopper for me in a remote area. Couple in frequent power outages and that it could be life threatening not having a vehicle during one, also an issue.