Which? has discovered that the battery life claimed by laptop manufacturers rarely lives up to reality, with our tests finding it often falls drastically short.

Almost all laptop manufacturers overstate their battery claims and in some cases battery life estimates were double what it got in the labs.

Overall Which? found that manufacturers are missing their claims not by minutes, but by hours. The most optimistic laptop manufacturers are overstating their battery life by 50 percent or more, leaving you searching for the power cable twice as often as you’d expect.

The Which? battery test involves draining the whole battery from start to finish, several times over, during various tasks.

One test involves watching films until the battery finally shuts down, another continually browsing websites over wi-fi.

The Lenovo Yoga 510 claimed battery life of five hours while Which? managed two hours, seven minutes.

The HP Pavilion 14-al115na claimed battery life of nine hours - Which? found it had four hours 25 minutes

The Dell Inspiron 15 5000 claimed battery life: of seven hours Which? tests: three hours 58 minutes.

The Acer E15 claimed a battery life of six hours Which? found it could only manage two hours 56 minutes.

Only Apple was conservative in its battery life findings The Apple MacBook Pro 13 claimed to have a battery life of ten hours - the Which test gave it 12 hours, But that is probably because it only takes a few hours before you can't listen to Coldplay any more,