Can Charging A Phone Kill A Car Battery. Playing a car stereo for hours can easily drain a car battery. That and any running lights cabin lights or other accessories will consume a lot more juice than your phone charger.
Smartphones typically use 5V when charging. If your car battery is old and only holds a 2 resting charge which is unlikely but possible your phone could easily kill your car. And when its full it will stop taking energy.
The few drive-in movies that exist these days tend to use FM radio transmitters for sound.
If your phone kills your car battery you need a new car battery. Charging It Overnight Which brings us to our next point. In some cases you may want to consider getting a brand-new phone instead of replacing the battery. 2 points 2 years ago.
