How long should a laptop battery last?

Laptops have come a long way.

The Kyotronic 85 produced in the 80s was little more than a calculator that ran on 4 AA batteries.

The batteries that you’ll most likely find in your TV remote would have given you 20 hours worth of work on this machine before needing to be replaced.

As modern batteries developed, laptops switched to the Nickel Cadmium (NiCad) in the 90s, allowing your machine to recharge. This battery works best when fully drained before charging again, making it vulnerable to “memory effect”. Memory effect meant that NiCad batteries which were recharged before they went dead would “remember” a lower max charge, running the length of time your machine would survive off-charge down quickly over time.

Today’s Lithium Ion batteries don’t suffer from memory effect and the latest in smart batteries and smart chargers know just when to start charging and when to stop to protect your battery best. But taking care of your laptop battery should still be a high priority to get the best out of your machine.

Battery overestimation

A Which? 2018 study found that five out of six laptop brands were overestimating their models’ average battery life. HP and Dell models tested lasted over 30% less time than they claimed whereas Apple lasted 20% longer.

Companies and reviewers each have they own battery testing standards, meaning that results will vary so battery life shouldn’t be your only measurement when choosing a machine but knowing how to keep it in top condition should mean your battery stays healthy and running for longer.

How long should a battery last and which one is right for you?

We’ve put together a brief history of the laptop battery, pitted the three most popular batteries against each other and compiled a list of some of the best battery life laptops according to CNET.com’s rigorous testing.