Given an on-the-grid, non-solar house, is it more energy efficient to charge your phone in your house or in your car? If there would be a difference for gas-powered and electric vehicles, please explain that as well.
In: Technology
More efficient to charge in your car, but the difference is an irrelevance compared to if you spend two seconds with your door open thinking about it and hence make your heating or air conditioning work harder.
What hasn’t been said so far is that most (all?) new internal combustion engine cars can choose to excite the alternator while braking, and de-excite while accelerating or coasting. This way, if the battery has a high enough charge, the alternator is only run while slowing down, using the kinetic energy you’re trying to get rid off anyway.
In this regard the charging would truly be free since it uses the energy that would otherwise be converted to heat in your brake discs.
This is a confusingly worded question.
If your question is whether a car or a power station is more efficient then the answer is a power station.
If your question is whether it is more efficient from a cost point of view to charge your phone in your house or in your car while you’re driving then that is a more interesting question.
I don’t know the answer to that and hopefully someone can do the maths but I’d imagine that an already running car would be wasting more power than a phone can draw so it wouldn’t actually add any additional fuel cost to your journey. Whereas there is a small cost on your electric bill to charge the phone at home.
It won’t make much difference, but the most efficient would be charging from the house. The large-scale nature of power generation like that means there’s less overhead per watt generated. Second would be charging from the electric car, because it’s being charged by the grid, and is providing voltage directly.
The worst would be charging from a gas car, because 70% of the energy in the fuel is wasted as heat. They’re horrifically inefficient. Of course, any heat engine will suffer from this (including the power plant), but a car is less efficient than that even.
It would take a *lot* of charging to notice any difference in cost.
Original intent of my question involved charging the phone off the car while driving, though even if one wasn’t driving you could charge off the car battery without turning on the car rather than starting the car engine which, of course, would be crazily inefficient.
It’s interesting there isn’t a consensus answer to this. I did wonder if the charge from the car would somehow be free in the same way the heat in the car is “free.”
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