Laptop battery lifecycles

To charge or not to charge? That be the question...

I'll start my first tip by talking about laptop battery wear.

First, a quick trick on how you can check your current battery life (also known as full charge capacity) for Windows users.

  1. Open up a cmd prompt. (Start -> Write "cmd" in the Search box and then press Enter)
  2. Write "powercfg -energy" and then press Enter.
  3. After 60 seconds a file (energy-report.html) will be generated containing a basic report. (the full path will be shown after it will be created)
  4. Go into the folder and open the file (it should start automatically with your browser)
  5. Scroll down to "Battery:Battery Information" (or something of the sorts) and you will see 2 key values:
  • Design Capacity 48400
  • Last Full Charge 45496

(the actual numeric values are for my case)

After a quick division you get the current battery life: 45496 / 48400 = 94% life left. That basically means that my current life is only 94% of the one when it was produced.


Of course, most people want to maximize their time spent on the computer and minimize the battery wear and tear so here are some basic tips on how to keep the life for Li-Ion batteries (most on the market):

  1. Each discharge cycle lowers the battery life, so avoid unnecessary wear.
  2. Try to keep your laptop in a cool place or get a stand for it. Heat accelerates the wear on the battery.
  3. If you plan on using it in only one place with a constant power source for periods longer than a few days, consider removing the battery. Best way to do this is to make sure it is currently ~50% charged before removing the battery (too high or low values tend to accelerate the wear for long periods of time) and then you should store it in a dry place at room temperature or even below. Batteries also tend to discharge at a slow rate even when not used so once a month it's recommended to charge it back to ~50% and then return it to storage.
  4. When not on external power, always use a brightness level only enough for clear visibility and try to close all unnecessary programs. (services, auto-updaters, taskbar programs)
  5. Customize your power plan settings for battery power so your laptop won't consume more than it should.
  6. Don't leave CDs/DVDs in the reader if you're not using it.
  7. Turn off Wi-Fi/Bluetooth or other services that you're not using.
  8. Sleep/Hibernate - Use sleep when not using your computer for periods of time smaller than 5-10 minutes. For more than that it is recommended to use hibernate, it saves a lot more power. (the setback is the time it takes to enter and leave the state, the computer needs to dump all the data saved in the RAM to your drive, and then when resuming, back to the RAM again; this way the RAM is powered off, hence the extra power saving)