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Comment by stcredzero | Hacker News Reader

My friends think I'm dowdy. Until recent years, I was very conservative about estimates. Every "event" in a trip adds 5 minutes, no matter how "nothing" it seems. I was often too early, but never late.

A Tesla S with the 260 mile battery, I would treat like a car with 130 miles range. Plenty for an around town commuter and errand vehicle. A Leaf, I would treat like a 50 mile range car.

Also, why don't those things come with a propane heater? Electric heat makes no sense.

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Having to put a propane heater into a shiny, high-tech electric car would be a marketing disaster: it would emphasize that battery capacity was something that drivers have to worry about under normal driving conditions. Plus, Tesla could no longer claim that their car had zero CO2 emissions.

> Having to put a propane heater into a shiny, high-tech electric car would be a marketing disaster: it would emphasize that battery capacity was something that drivers have to worry about under normal driving conditions.

Battery capacity is, though, just like it is something you think about when driving a petro fuel car. Drive a diesel? You need to think about gelling fuel in Vermont in January. For a supposedly well educated technological society, an awful lot of us seem to engage in magical thinking.

Knowing nothing about heaters, I'm curious: why does electric heat make no sense? My intuition would be that an electric heater would require far fewer components (especially considering the battery is already in place), be less dangerous, and require less maintenance. What is the relative efficiency of electric heaters to propane heaters?

Electric heat via resisters is very simple, but very inefficient. (EDIT: Thermodynamically space-heaters are 100% efficient, since they always convert their source energy into heat. They are inefficient from a monetary point-of-view.)

You can do electric heat via heat pumps, but it requires more equipment and it doesn't work if it's too cold. You can get about a 4 to 5 advantage over plain resistance heat.

Gasoline engines lose a lot of energy to waste heat -- but sometimes that waste heat is exactly what you want.

> (EDIT: Thermodynamically space-heaters are 100% efficient, since they always convert their source energy into heat. They are inefficient from a monetary point-of-view.)

They're a disaster from a range point of view.

I don't think they "make no sense", and I'm not sure a propane heater is the answer, but an electric heater is going to require the use of battery power otherwise used for getting you from point A to point B.

In terms of how big a chunk they take out of range, they're a disaster.

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