If you're on the hunt for a new laptop, there are many things to consider. These include screen size, price, RAM and of course, battery life. It can be hard to make a decision, but Which? magazine has now made it even harder.

The publication has found that laptop manufacturers exaggerate the battery life duration significantly. 

"Almost all laptop manufacturers overstate their battery claims. In some cases, the battery life estimates were double what we achieved in lab testing," the company said. 

They tested 67 models over a year long period. The tests were carried out as the laptop was actively used for web browsing over wifi until the battery died. 

Here's a breakdown on brands tested: Acer (8); Apple (3), Asus (8), Dell (10), HP (12), Lenovo (20), Toshiba (6).

Findings

Every laptop featured in the experiment was tested at least three times. The findings from the tests, which ran from January 2016 are rather startling. 

"Overall we found that manufacturers are missing their claims not by minutes, but by hours," says the report. 

Which? found that:

• Acer E15 lasted two hours, 56 minutes. Claimed: six hours
• Apple's MacBook Pro 13 lasted 12 hours. Claimed: 10 hours
• Dell's Inspiron 15 5,000 lasted three hours, 58 minutes. Claimed: seven hours
• HP's Pavilion 14-al115na lasted four hours, 25 minutes. Claimed: nine hours
• Lenovo's Yoga 510 lasted two hours, seven minutes. Claimed: five hours

Dell responded to queries from Which? about its claims on battery performance with the following statement, ‘It’s difficult to give a specific battery life expectation that will directly correlate to all customer usage behaviours because every individual uses their PC differently – it’s similar to how different people driving the same car will get different gas mileage depending on how they drive.’

HP said that is battery tests ‘uses real life scripts and runs on real applications like Microsoft office' and that the exact specifications, such as screen resolution, will impact the results for each model.

Which? also found that Apple MacBooks are one of the few who met or exceed their battery claims.