3 ms·

That is also true of a gas vehicle.

egberts1 5y ago
You can start, heat, then turn off. And this can go on for 72 hours on a full-tank in 28 degree weather. Bet you can’t do that with today’s electric car.
- leoedin 5y ago
  Here's a video with a Tesla Model 3 keeping the cabin at 21 C for 71 hours in -4 C (24.8 F) weather. https://www.youtube.com/watch?v=bpzB3RbjuHI https://www.youtube.com/watch?v=bpzB3RbjuHI That car has a heat pump for cabin heat, which has a coefficient of performance of 3-4. That means you only need 1/3 of the heat energy as electrical input. Compare that to a gasoline engine, where almost all the energy in your fuel is wasted as heat outside the cabin. I don't know what fraction actually makes it into the cabin - but I'm guessing it's single digit percent.
  - SigmundA 5y ago
    Heat pumps drop in efficiency the colder it gets and only work down to a certain temp. If the outside coils get too cold they freeze up preventing it from functioning properly. would be interesting to know how cold the Tesla heat pump can operate down to and if it has resistive backup. Edit: looks like the heat pump only works down to about 14F then it runs the heat pump in recirculation mode to basically turning it into a resistive heater with COP 1, its also seems to have 12v aux heat strips.
- SigmundA 5y ago
  You can run a 1500w resistive heater for 50 hours on a 75kwh battery. I run a 1500w heater in my 30ft RV and it holds comfortable temps down to freezing, in a small vehicle it should have no problem even down to very low temps, 750 watt might be plenty to keep the interior at a safe temp.
- chrisseaton 5y ago
  > Bet you can’t do that with today’s electric car. Do you realise an electric car comes with a massive electric battery that you can use to run the heater? Unlike a petrol or diesel car, you won't be risking poisoning yourself while you sleep either.
  - kortilla 5y ago
    > Unlike a petrol or diesel car, you won't be risking poisoning yourself while you sleep either. Unless you’re doing this in your garage, that’s not a risk
    - SigmundA 5y ago
      Snowbound car CO poisoning happens all the time: https://montrealgazette.com/news/local-news/carbon-monoxide-killed-three-men-in-snowbound-cars-coroner https://montrealgazette.com/news/local-news/carbon-monoxide-...
    - chrisseaton 5y ago
      Very dangerous misunderstanding! Snow packed up around a vehicle has the same effect as being in a garage and definitely can cause lethal poisoning. When I'm doing multi-day off-roading we carry exhaust hoses to take the fumes far away, even though we're outside the whole time.

You can start, heat, then turn off. And this can go on for 72 hours on a full-tank in 28 degree weather. Bet you can’t do that with today’s electric car.

leoedin 5y ago
Here's a video with a Tesla Model 3 keeping the cabin at 21 C for 71 hours in -4 C (24.8 F) weather. https://www.youtube.com/watch?v=bpzB3RbjuHI https://www.youtube.com/watch?v=bpzB3RbjuHI That car has a heat pump for cabin heat, which has a coefficient of performance of 3-4. That means you only need 1/3 of the heat energy as electrical input. Compare that to a gasoline engine, where almost all the energy in your fuel is wasted as heat outside the cabin. I don't know what fraction actually makes it into the cabin - but I'm guessing it's single digit percent.
- SigmundA 5y ago
  Heat pumps drop in efficiency the colder it gets and only work down to a certain temp. If the outside coils get too cold they freeze up preventing it from functioning properly. would be interesting to know how cold the Tesla heat pump can operate down to and if it has resistive backup. Edit: looks like the heat pump only works down to about 14F then it runs the heat pump in recirculation mode to basically turning it into a resistive heater with COP 1, its also seems to have 12v aux heat strips.
SigmundA 5y ago
You can run a 1500w resistive heater for 50 hours on a 75kwh battery. I run a 1500w heater in my 30ft RV and it holds comfortable temps down to freezing, in a small vehicle it should have no problem even down to very low temps, 750 watt might be plenty to keep the interior at a safe temp.
chrisseaton 5y ago
> Bet you can’t do that with today’s electric car. Do you realise an electric car comes with a massive electric battery that you can use to run the heater? Unlike a petrol or diesel car, you won't be risking poisoning yourself while you sleep either.
- kortilla 5y ago
  > Unlike a petrol or diesel car, you won't be risking poisoning yourself while you sleep either. Unless you’re doing this in your garage, that’s not a risk
  - SigmundA 5y ago
    Snowbound car CO poisoning happens all the time: https://montrealgazette.com/news/local-news/carbon-monoxide-killed-three-men-in-snowbound-cars-coroner https://montrealgazette.com/news/local-news/carbon-monoxide-...
  - chrisseaton 5y ago
    Very dangerous misunderstanding! Snow packed up around a vehicle has the same effect as being in a garage and definitely can cause lethal poisoning. When I'm doing multi-day off-roading we carry exhaust hoses to take the fumes far away, even though we're outside the whole time.