Do I save energy by having my laptop unplugged and working off the battery?

Question

Please give me some stats to prove it makes a difference if I unplug my laptop for an hour or two and work off the battery. Or does it not matter and as soon as I plug it in it pulls more energy to charge it again? Thanks.

Answer 1

If you charge at night and use your computer during the day, you'll be running on cheaper electricity (3x or 4x cheaper).  Also, you'll be charging while the electric companies have less demand and extra electricity.  Remember, they can't store it and use it later.

It's kind of like a supermarket.  If you go during the day it'll be busier and they'll need more cashiers.  If you go at night they won't need any more cashiers since shopping demand at night is minimal.

Answer 2

If you unplug the power supply from the wall while you are using the battery, it will save energy.

The power supply that comes with the notebook computer is really a transformer. It uses electricity when it is plugged in whether you have a computer attached to it or not. When the battery is fully charged on your computer, that transformer is still using electricity even if the computer is turned off. So anytime the battery is charged and you unplug the transformer you will save electricity.

Most of the power supplies that come with a notebook computers use about 70 to 90 watts of electricity. That's like leaving a light bulb on for as many hours as you leave it plugged in. You probably turn out lights when you are not using them, so you should unplug it from the wall when your battery is fully charged or else plug the computer power supply into a surge strip that has a switch that makes it easy to turn off/on.

Some people leave their phone chargers plugged into the wall all of the time, too. The same thing with those--they are also transformers and use electricity while they are plugged in even though you are not using it to charge a phone all of the time.

So unplug all of those little transformer things when they are not in use.

Answer 3

it doesn't matter if you plug it in or not.

Answer 4

Imagine having a barrel. You connect a water pipe to the top and a drain to the bottom, and drain the water away at the same rate the barrel is filling up. That's like using the computer plugged in to the socket all the time. If you close the pipe at the top and then drain the water away until it's empty, well, that's like using the computer on the battery. But then you'll have to fill the barrel up again, so in the end, you'll use the same amount of energy (the same amount of water will have gone through the barrel).

Answer 5

good question

Answer 6

IN OVER ALL POWER

    It cost about 40% more to charge the battery than it would to run off AC.

Answer 7

Here are the numbers I ran against my own laptop:

Power use is listed in watts per hour

(The Draw number is the important one)

Maximum Plugged In

Draw: 156w--Heat: 66w--Output: 90w

Full Power/No Recharge

Draw: 102w--Heat: 43w--Output: 59w

Min Power/No Recharge

Draw: 47w--Heat: 20w--Ouput: 27w

Full Power/Recharge

Draw: 148w--Heat: 63w--Ouput: 85w

Min Power/Recharge

Draw: 116w--Heat: 49w--Output: 67w

Battery - Max Power

Draw: 59w

Battery - Min Power

Draw: 27w

My laptop power supply draws 1.3amps at 120v that works out to 156w. A maximum output of 90w of that goes into my laptop the remaining 66w is heat. 43% of the power that it uses is wasted.

Unplugged laptops generally go into power saving mode. They will slow the CPU speed, stop the hard drive more often and lower the brightness of the screen (big power savings) all that good effort is lost when you remember that the power supply you use to charge the battery is making more heat . When you reattach it to the power adapter it goes back to Full Power Mode, and recharges the battery as well.

As you can see from the table above, the best way to save money and power is to remove your battery when it is fully charged, modern laptop batteries can hold their full charge for months. Use the power saver feature to make it think it is running on battery and in my case, I can save 900w per 8 hour work day.

Using your battery until it is dead then recharging it will wear it out quickly, in some cases less than a year, which can be very expensive to replace. Removing it when the laptop is on wall power will not cause it any additional stress, it may stress you if leave the home and forget to grab take it with you :)

Remember that the DVD drive, wireless and screen brightness use the most power. Limit their use and you will save a little more power.

Hope that helps!

Answer 8

it doesnt matter. just charge it over night and you'll be fine for an hour to 2