One of the most difficult aspects of a mobile computer is keeping it mobile. I'm sure everyone knows what I'm talking about - how many of you carry around your power bricks along with your UMPC just to plug it into the nearest wall outlet in order to make sure you don't run out of battery power?

What can you do to help?

First, you can optimize how you use your computer. First is to select the right power settings - Windows Vista provides three default power plans that have unique settings for AC and DC power states. Normally "Balanced" will work just fine, but if you want to try to get a little more battery life you can use "Power saver". Or you can go and modify those settings individually. You can reduce performance but save power by stepping down the CPU - (Power settings, change power plan settings, Advanced settings, Processor power settings - change Maximum processor state down from 100% to 50%). Secondly, drop your backlight brightness. If your Windows Vista display driver supports this it will appear under "Edit Plan Settings" in your Power Options Control Panel. You can increase your lifespan by tuning down the search indexing service (Advanced power settings, Search and Indexing, modify on battery to power saver).

Next, reduce the power hungry tasks. Your top power consumers are your CPU and LCD panels, but everything draws power. If you have external USB devices that you aren't using, unplug them (they draw system power to run). If you aren't using your wireless card you can open up Windows Mobility Center, find your network card, and "Turn wireless off" (again, this appears if your hardware drivers support this functionality). Close down applications you aren't using - even background applications take battery life.

Finally, you can monitor your power consumption and the health of your battery. In the end, there's only so much you can do with how you use your computer (you still have to use it, right?). One case I've frequently seen is battery degredation. While lithium-ion batterys (what most of us have in our laptops) don't have the old "memory" traits, they do lose maximum charge capacity over time. You may see this where a laptop that is 4-5 years old may get a small fraction of battery life (I've seen people run from one power outlet to another due to this). You should consider the battery inside your computer as a part you need to maintain, and perhaps replace, through the lifetime of your mobile pc. So, when do you replace it? I honestly can't give a solid answer, but I would consider it about every 2-4 years, depending on the battery.

To help out a little, I've created a Windows Vista Sidebar gadget and posted it to http://gallery.live.com:

http://gallery.live.com/liveItemDetail.aspx?li=38ad04cf-2c94-43bb-9899-51814beaadbf&l=1

In addition to displaying your battery information (% remaining, time remaining when unplugged, AC/DC states) it also displays your tired battery state and lets you know (as a percentage) how much charge you are getting compared to new. This should help you determine if the loss of computing time is worth purchasing a new battery. Plus, it is far easier to see at high resolutions on small screens than the system battery icon in the tray.

Thanks,

Ross