The Life of a Computer Battery

Listen to the podcast

Question: How do you prolong the battery life on a laptop computer? Is it true that leaving the laptop plugged in all the time will ruin the battery life?

The IT Guy says:
This is a really good question, and the answer is the always-helpful "it depends"!

If your laptop is older, it will probably have a nickel-alloy battery. For those kinds of batteries you want to completely run the battery down about once a month. If your laptop is newer, it will probably have a lithium-alloy battery, and it's best to recharge those batteries when they are partially run down. If you know how to remove the battery from your laptop, it will say what kind of chemistry it uses (probably in teeny-tiny print). If it has nickel, it will say NI-something, and if it uses lithium it will say LI-something.

You will often hear people talk about something called "the memory effect", which means that if you regularly recharge a battery before it runs all the way down, it will develop a pattern of running out more quickly. As I have researched this, some experts say it's real and some say it's an urban myth. In all cases, everyone agrees it's not an issue with lithium-based batteries.

The greatest threat to the lifespan of your laptop battery seems to be overcharging. Heat shortens the life and power capacity of batteries, so once your battery is fully charged, disconnect your power cord. Even under the best circumstances, however, a laptop battery will degrade over time, especially the newer lithium batteries. Expect to have to replace them after two or three years, with the time you can run on battery getting shorter and shorter as time goes by.

Next Tip: Deleting Email — Permanently