can you charge an i-pad for 2 or 3 hrs. without having the car running. Will it drain the battery if you do?
If your battery was on its last legs, it could push it into the grave. Other than that, I don’t think it would hurt the battery.
As long as your battery is reasonably healthy, this will not drain the battery in your car. That charger probably draws 3-5 amps, while your car battery carries 550-750 amps, and your starter draws less than 200 amps. No worries unless your battery is already knocking on death’s door.
It shouldn’t hurt anything, but I wouldn’t necessarily try it when the outside temp is -10 degrees. A note: Amperage (cold cranking amps) is a measure of how much power the battery can deliver all at once at a specific temperature. It is not a measure of how long it can deliver power. If you draw 2A from your battery for long enough, it will be dead. There is no time unit included in amperage. That is why your electric bill is measured in watt hours and your car battery capacity is measured in amp hours.
It shouldn’t hurt anything, but I wouldn’t necessarily try it when the outside temp is -10 degrees.
You don’t want to leave a LCD display outside in -10 anyways…
As a general rule, if you expect your car to start when you get back, don’t leave anything on that could drain the battery.
Why can’t you charge it while driving the car, or indoors using an A/C outlet? Even IF mark9207 is right, why take the chance?
Some after-market car chargers can reduce the life of cell phone batteries. Something to do with voltage regulation, maybe. You can google it and find out.
I have to be reminded that the battery in a car is a starter battery and does not like to be drained very far w/0 charging. But, like leaving a small light on for two hours, everything except proper storage is hard on a battery and our economy is based upon replacement. So, for light loads, short times and recharging soon after (driving), there should be little concern in moderate temps and a battery in good shape.
Besides, working I pads are more indispensable it seems then working cars these days.