pnichols wrote:
John & Angela wrote:
"Assume heater draws 1kw that would consume 1kwh every hour. So it would take 10 hours of parking lot traffic to consume 10kwh of charge (~40 miles of range). In other words, you'd lose ~4 miles for every hour you're stuck in traffic.
That seems way too little to heat an automobile (with no engine radiated heat to help) in 0/10/20/30 degree temps like a lot of the U.S. may experience during winters ... but I haven't done an analysis.
Our car heater really puts out the heat if needed ... way more when needed than the 1500 watt 120V AC heater we use in the RV when on hookups. 1500 watts of resistance heat is around 120 amps of 12 volt RV battery DC power, which of course means that's it's not feasible to run a 1500 watt heater from an RV's battery bank. I don't know what a typical EV lithium battery bank's output voltage is. I'm pretty sure it's much more than 12 volts DC, but even so the amperage coming out of the bank has to be high to run a resistance heater.
It seems like heating an EV on, say, a three hour trip in Northern U.S. winter cold would be a massive drain on it's battery bank. An air-to-air heat pump will reduce the heating (and cooling) load somewhat, but an ATA heat pump will not heat much at all below about 35 degrees F.
Yah. You pretty well nailed it. So the leaf for example uses a heat pump so doesn't use much power till it gets cold at which it uses resistance heat only at 1000 watts. think it would be a bigger draw in very cold weather (electric seats, electric steering wheel) which is why they are not suitable for minus 30 or colder environments. I believe the nissan leaf actually shuts the car down at minus 35. I would recommend a conventional car for those environments. Thankfully where we live in Canada that is not an issue.
Our little two seater does not have a heat pump but just a resistance heater. It's a pretty small cab so easy to keep warm. We also preheat before we leave (just activate from iphone) while it is still plugged in. In colder temps it is best to count on a loss of 1/3 of the range. Buy the car with the range that suits your needs in the worst case sceenario.
By the way, most EV's have electric seats and some steering wheels to save power.
Re the voltage of the battery. It is 403 volts for the leaf and high 300's for the smart.
One other thing. Norway is a cold country. One third of all new car sales (expected to be half this year) are electric vehicles so they obviously work in cold climates.
Hope that helps.