Macbook Battery Power Consumption

Hi guys,

There are alot of questions on here based around the whole "should I drain my battery or will it be ok plugged into the outlet all the time etc", but I cant seem to find the answer to the following question:

How much energy is used to keep the charger 'trickling' between 95% and 100%? I assume it would use more energy to fully charge it from below 10%, but does anyone know what kind of a difference in consumption it would be?

I only ask because im trying to keep energy bills down this year since a massive hike in prices for the UK and I tend to have the macbook fully charged most of the time, sitting on or around 100%, plugged in constantly. Would it use very little with this method?

Thanks

It is better to keep it plugged in as often as you can, and just calibrating the battery once a month.

The amount of energy it is using while charging or in fully charged state when plugged in is dependant on use, and your energy saver settings.

Anywhere from 15watts approx to 60 watts approx
Min being low display light, idle, etc
Max being full brightness, wifi, bluetooth, heavy load, etc
It has the energy star version 5.0 rating, which you can google and get lost in, or just know that it's not going to affect your hip pocket noticably.

If you really want to see how little it uses, turn everything off (fridge, hot water, all apliances, all lights, etc. Go make sure that your power meter isn't spinning to see if you've missed something, and then plug your Mac in, and go have a look again. You will see that it is moving slower than a snail's pace.

Energy saver light bulbs, timer on your hotwater service if it's not an instant gas unit, and appliances that you are not using off instead of on standby, lights off in rooms that you are not occupying, and refridgerator set accordingly to the climate.... that is how to save money on the bills. Your laptop won't have any significant impact on your bill.

Keep in mind that I used to be a sparky many moons ago, however, these links may help ease your mind if I haven't:

http://michaelbluejay.com/electricity/computers.html
http://www.upenn.edu/computing/provider/docs/hardware/powerusage.html
http://www.girr.org/mac_stuff/laptop_power.html

Thanks 6string, well explained, in depth answer that has indeed eased my mind