Boost Your Battery

Going on a journey and want to use your laptop on the way? Working in the field with no power outlet? Maybe you are sitting in backyard blogging, as I am, and don’t fancy getting out of your garden chair to get the power supply hooked up. Well, you can never extend your laptop battery life indefinitely, clockwork and solar power are not yet a viable option for such power-hungry devices but there are a few ways you can make it last just a little bit longer.

Laptopmag offered five tips for improving battery life some time ago:

Tip #1 Power down the display - reduce the brightness in other words
Tip #2 Turn off unused devices - you can disable your DVD drive, for instance, or that wireless connection if you do not need network access
Tip #3 Decrease hard drive activity - defrag and optimize your swap file to reduce activity
Tip #4 Disable startup items - moreover strip away all applications that you are not using that would otherwise use the CPU and hard drive and so waste power
Tip #5 Condition the battery - easier said than done, but worth a punt

I wanted to add a little extra tip to their #3, if you have a USB stick that uses less power than your laptop’s hard drive you might be able to save a few milliwatts and so extend battery life by seconds, if not minutes, by running the documents you are working on from the USB stick rather than the hard drive. But, do the figures stack up?

They might well do that. I just discovered a post from Robin Harris who does the sums over on Storage Bits. According to Harris, an idle laptop hard drive (5400 rpm) runs at 3.3W, much higher if it is spinning up. He does not say what it consumes when working hard, but we could assume that at most it doubles. So, 6.6 W. A USB stick consumes nowhere near that running at up to 50 milliwatts idle or working (that is just 0.005 Watts.

However, before you grab your stick and shove it in the slot, remember that adding a USB will push up CPU usage just as a hard drive does if not more so, higher CPU usage means higher temperature, which means more fan activity, and fans certainly do use more than a few milliwatts. It probably does not make sense to use a USB as a kind of external HDD unless you need the other features of the USB.

That said, one of the easiest ways to boost laptop battery life is simply to power down, grab a beer and sit back in that garden chair to soak up the rays. Fine for those of us who have finished blogging for the day but not an option if you are stuck on a journey or powerless in some field.