There are some phone cases that make your handset look pretty, some give it a valuable layer of protection from the elements and droppage, while some just help you actually receive some kind of network signal. However, there are few that add extra battery life.

Samsung has devised the EBB-U10 power pack for its Galaxy S Android phone, which, when bolted onto the back, adds a stunning 8.5 hours of talk time to its existing battery.

There are currently few concrete details on how it works, but Pocket-lint suspects that it either slots into the micro USB port at the top of the handset, or acts kinetically, like a PowerMat, transferring new charge into the built-in battery.

The add-on does add an extra 70g more to the weight of the device, but at least that makes it more suitable to fend off muggers and/or Apple fans.

Currently only announced in Germany (but we wholly suspect that it'll also be available in other territories), the EBB-U10 bolt-on will be available in September for around 70 euros (£57).