Batterylife Activator

If you've had your mobile phone or notebook computer for more than a year, you may have noticed that its battery doesn't last as long as it once did.

The Batterylife Activator is a special gadget that claims to reverse this trend and revive your battery.

It's a sticker that you must attach to at least 80 per cent of one side of your battery to be effective. It can be cut to fit with scissors if it's too big.

Some patience is needed as the Activator takes between five and 10 charges before the effects can be seen. We tested the Batterylife Activator with a notebook that was a couple of years old.

Before we added the sticker, the notebook consistently scored 2 hours 20 minutes in our battery test. After the patch was applied, this rose to a maximum of 18 extra minutes. We ran the test 20 times to double check the results, as we thought the improvement rather inadequate.

When we asked how it works, the manufacturer said it wasn't quite sure. Batterylife told us that the process was discovered by accident and that it had been assured that the sticker makes no harmful emissions and is quite safe to use. Its lack of knowledge is hardly reassuring.

This is an odd product that we're very sceptical about and, going on our notebook tests, it's not worth the money for an extra 18 minutes of battery life.