# Push button power consumption

Hi,
I connected a push button based on this tutorial:

I am using the push button to sense when the lid of a music box is opened. That means that the push button is depressed, and released for lengthy amounts of time.

Specifically, when the lid is closed, and the box is inactive, the push button is pressed.

I would like to keep the box always connected to the electricity.
I was worried about the power consumption.

I am using a 12V/3A power supply.
As far as I can tell from the sketch, the button is connected as such:
5Volts --> 10 KOHM -> GND.
I think that the circuit will draw 2 milliamps. (am I right?)

BTW: As long as the button is pressed, the arduino loops on one second delays, so i don't think that the Arduino itself is an issue. (am I right in this assumption?)

Is 2 milliamps alot?
Can I leave this thing connected for long durations, or is it drawing too much electricty?

Also, I might switch to a 9V battery sometime soon. How long can a good (duracell?) battery last like this?

5/10 is 0.5, not 2.

The fraction of a milliamp is probably smaller than the power consumption of the wall wart you're peeping it with.also, if you're not sleeping the chip, that will be dressing significantly more than that resistor. Also, if it's got a power led on the board, that's 10-20mA (that's why people running on battery remove the power led from pro minis).

None of this power consumption will have a noticeable impact on electric bills. You're billed by the kilowatt hour. 5v times even 50mA is 250 mW. 6 watt hours per day. 25 cents a year.

9V batteries are 100mAh or something like that. Measure the total current consumption of your
whole circuit to be able to calculate the like endurance. Remember battery capacity figures are
best-case values, only apply to brand new or freshly charged batteries at a particular temperature
and discharge rate... Assume a real battery will have 1/2 its nominal capacity by the end of its life
and you'll be less dissappointed. Different kinds of rechargable battery have different rates of
capacity loss with age/use, and all are permanently damaged by over discharge and over-charge...

In other words, forget the 9V ‘Duracell’ battery if you want to leave the circuit powered for long durations. You’ll be replacing the battery at least a couple of times a day.