For sure you have heard or read, at least once, recommendations about how to improve the battery life of a laptop, mobile phone, or whatever gadget. But I’ve detected that several times that recommendations are wrong, and they do more harm than benefit to a laptops battery. That’s because battery technology has been changing along the years, and the methods of taking care of them also. So, I’ll try to summarize some of the most basic up-to-date tips to increase the life of a laptop’s battery. Before applying them, just check that you battery is of lithium-ion (Li-ion) type.
The easiest and faster way of improving the power efficiency of the laptop, is at software level. With the PowerTOP application we can not only monitor which software is responsible of our CPU cycles and hard disk spinning, but also (and more important) tune several parameters related with the energy. For example, enable the auto-suspend of an external USB device when not in use, or an energy saving feature of the wireless card.
After playing with it, you will probably notice that the settings are not saved, and after rebooting you have to run PowerTOP and set everything again. Solution: if you run PowerTOP with the –html option, it will generate an HTML (surprise!) report with all the command line instructions to set each tunable. So, then you only have to add these commands to an init script (for example, /etc/rc.local on Arch Linux), and you’re done!
Just a last tip: do not enable autosuspend for an external mouse… it’s really annoying.
If you are like me and usually run your laptop connected to AC, your battery it’s probably almost always charged at 100%. This is not good. But but be optimal, is having it charged at max of ~85%, and then let it discharge by its own until it reaches ~35%. About “telling” you laptop to follow this charging cycle, I only know how to do it with Thinkpads, which is setting:
echo 40 > /sys/devices/platform/smapi/BAT0/start_charge_thresh echo 80 > /sys/devices/platform/smapi/BAT0/stop_charge_thresh
having Tp smapi installed. Details about how to implement it on a script can be found on the ArchWiki.
Actually, the best way of keeping a battery in an optimum state, when not in use, is having it at 40% of it’s charge and storing it on the fridge. If you try that, please put it on a sealed plastic bag, with some rice to absorb humidity!