How to minimize power consumption by unused devices?

November 19, 2012 By | Add a Comment

External devices

For external devices such as USB keyboards/mice, USB memory sticks, and ExpressCards, the best way to save power is to physically disconnect them from your laptop.

Integrated Wi-Fi adapter

If you do not use network, you can disable Wi-Fi adapter. Your laptop probably has a mechanical switch or function-key to control Wi-Fi radio. By disabling Wi-Fi, you usually can save 10% or more battery life.

Integrated Bluetooth adapter

If you have a Bluetooth device and use Bluetooth functionality occasionally, you can just leave the Bluetooth adapter ON all the time. Integrated Bluetooth adapters are usually well power managed by its device driver and, if no device is paired, it automatically enters power saving mode. (Please note that this statement does not apply to plug-in type USB Bluetooth adapters) Once the adapter is in power saving mode, its impact to the battery life is very small.

If you do not have any Bluetooth device and you know that you will never use Bluetooth functionality for long time, you can disable Bluetooth adapter with mechanical or software switch. It will give a little bit more power saving. (but, not much)

Other integrated devices (camera, finger print sensor, audio, etc.)

If the device and its device driver are properly designed, you usually do not need to do anything. Device driver will put the device into power saving mode when the device is not used and impact of the device to the battery life is very small or nothing. Some web articles recommend you to disable unused devices in the Device Manager. It sounds reasonable recommendation, but you should not do that. If you disable the device in device manager, that device may not be put into power saving mode. It often takes proper device driver’s help to put the device into power saving mode, but if you disable the device in Device Manager, device driver is not loaded and cannot put the device into power saving mode.

Generally speaking, if you are using a laptop from decent PC vendor and you are using the latest device driver from that PC vendor, you do not need to worry too much. Just leave the idle device as it is (except for the Wi-Fi adapter and external devices) and you are not loosing much battery life.

But, if you want to make sure that the devices and device drivers in your laptop are properly power managed, please try Battery Life Maximizer. It will check if the devices are really in power saving state and, if not, let you know how to fix it.

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