Why Does Laptop Batteries Degrade And Lose Capacity Over Time?

macbook_pro_batteryThe battery in your shiny new MacBook, or whatever laptop you might be running, is most likely the lithium-ion type battery. Compared to other batteries, lithium-ion batteries carries a lot of energy in a very small space, a one kilogram battery can supply 150 watt for an hour.

Lithium-ion batteries degrades over time. No matter how much you use the battery, it’s capacity will decrease with approximately 20% a year. You see, the battery is a actually a very small chemical factory, where many things can go wrong. Even the slightest traces of water can lead to salts being made, which destroys the cathode (the negative electrode in the battery).

The damages to the cathode makes the internal resistance of the battery increase until the battery can no longer provide your laptop with power.

Much research is currently going into developing new batteries and chances are that we will be seeing batteries with much larger capacity than we have today as well as extremely fast recharging.

Here’s a chart that shows approximately how much capacity a lithium-ion battery will lose over a year if stored at a certain temperature:

0 °C (32 °F) » 6 percent
25 °C (77 °F) » 20 percent
40 °C (104 °F) » 35 percent

Tomorrow I will “reveal some of the secrets” on how to prolong the life of your battery – after all, it’s a part of your laptop worth usually $100-150, so why not try to get the best out of it. Subscribe to my RSS feed today so you don’t miss out on future posts 🙂

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