Title, why can we drive for hours and hours on end, with headlights, radio, a/c, etc. (besides stopping for gas, bathroom breaks) But when we leave a light on for as much as an hour, the car battery will pretty much die instantly.
In: Engineering
While the engine is running, a device called an “alternator” (or a generator in older cars) is recharging the battery and powering the electronics.
The battery itself is normally only responsible for starting the engine, and then it recharges. It’s designed to deliver a lot of power very quickly to crank the engine, it’s fairly inefficient at more menial work like powering the headlights.
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