06 August, 2014

Getting more time out of your laptop battery - Part two

In the previous post we've been talking about some of the more obvious ways to get a few more minutes, or maybe even an extra hour or so, out of your laptop battery. Things like movable components, wireless connections and display brightness all significantly influence how much time you will be able to spend editing your spreadsheets.
Here we will add some of less obvious options that can also help to redirect a bit of electrical juice towards things that you would want to use.

Shut down unneeded applications

If you're anything like me, you will probably have a few applications up and running all the time. The thing is that you may not necessarily perceive them as running, because they will reside in your system tray, all silent and inconspicuous. However all of them are consuming some system resources and with that electricity. What’s more, lots of these applications only make sense when your computer is online. Different cloud storage applications like Dropbox, Box, OneDrive, Google Drive and so on provide you with no benefit when you’re not connected to internet. What they will do, however, is to see if connection is available every so often. And that may actually be more power consuming than if they were connected and idling. Similar story applies also in regards with various communications applications like Skype, Viber, Yahoo messenger and the like. Seek out any such applications that you do not need while offline and close them. If your system is low on memory you may actually speed it up a bit at the same time. Just don’t forget to turn them on, when you’re back online J

Some of the applications that are constantly running can be found in the System Tray

Choose which graphics adapter is in use

Hmmm? What? You may not be aware of this, but lots of newer laptops actually have two graphics adapters. Especially if your laptop has an Intel i5 or i7 CPU. One is a so-called builtin graphics adapter and will be from Intel. The other is typically referred to as a “discreet” graphics adapter, since it’s an addon component and not directly integrated into the system board. Two main manufacturers of these are nVidia and AMD (formerly ATI).
Integrated adapter is typically more than sufficient for any “office” work that you have to do and is not power-hungry. Discreet adapter, on the other hand, can be useful for graphically-intense applications, such as games or other applications that do 3D graphics. But it’s also a power-hog and will drain your battery in no time.
Depending on your adapter manufacturer the process of selecting adapter might differ slightly, but in general you have two options. One is to assign applications to one or the other graphics adapter individually.

AMD driver allows for individual applications to be assigned to a specific graphics adapter
The other is to have the system choose the integrated graphics adapter automatically when you’re on battery power. Second option may be better if your consideration is solely to prolong battery power, but be aware, that it may degrade performance of some applications (especially games).

Choose type of graphics adapter depending on whether you're on battery power or not

Make sure your laptop doesn’t overheat

Some laptops are better at heat dissipation, some are worse. But heat is always a bad thing, on many levels, for a laptop. First thing is that electronic components will run more efficiently when they are cool. If they run more efficiently, they use less power. Also prolonged elevated temperatures can cause damage to internal components and things may start to fail. Second thing is that if your laptop heats up, its internal fan will turn on to cool it down and that will use up additional power. So keep your laptop cool.
How can you do that? Allow laptop to radiate heat. That is most easily achieved if it has least contact with flat surface and most contact with air (providing that the air is cool, of course). There are lots of products on the market that help you do that. There are passive laptop pads that simply enhance the natural airflow or active ones, that have builtin fans. Problem with those things is portability. I personally prefer a set of vacuum rubber feet that you can attach from below and they distance laptop from surface on which it rests, which increases its cooling area.

Cooling laptop feet
Make your CPU run more slowly

This one goes into a similar category as the graphics example above. Namely, reducing the performance of your laptop in order to conserve battery power, while still leaving sufficient amount so that you can do what you need to do.
CPUs today are probably overkill for most tasks, apart from some specialized ones. If you’re running your text-editing or spreadsheet application, then CPU power is one of the last things that you lack for. The problem is, that even if that is so, your CPU may not be aware of this fact. While it is true that CPUs have certain automatic flexibility that allows them to increase or decrease their frequency (and with that how much power they require), they usually do this in a fairly limited fashion in order to provide you with the snappiest experience. So in a battery-extending scenario we would want to throttle our CPU to a level where we can still do our tasks, but have CPU run at a fraction of its maximum rate.
This is something that can easily be achieved by creating or simply modifying a power profile. You know, that thing that you are aware of but have never used?
You can access power profiles either through Control Panel or from the battery icon I the System Tray. 

Power plan selection
There will usually be couple available. Select the “More power options” and then “Change plan settings” on the “Power saver” plan, when a new window opens.

Main Power Options window
On the next screen click on the “Change advanced power settings” and yet another window will present itself.

Advanced Power Options
Now scroll down until you reach the “Processor power management” section. There will be two subsections there, that we’re interested in. They are entitled Minimum and Maximum processor state. By default values will be 5% for Minimum and 100% for Maximum, both when the system is on battery power or plugged in. You will probably want to leave Minimum set to the default value. Maximum value, however, should be decreased. I found that for me 50% works fine, but you may go even lower. Depending on what kind of performance still suits you and how powerful your system is.

Processor power management settings
Once you set the values, confirm them, close all the dialogue windows and in the system tray choose your Power saver profile.

Here we are. With some or all of these approaches you will definitely be able to extend your work (or play) time a bit. That’s always nice on those long flights or on sunny afternoons, when there’s no power outlet around.


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