Sometimes you don't know you want something until you actually get it. In this case, it's the Devotec Solar Sound Bluetooth Speakers, which have been a god send over the past few weeks.

The speakers themselves have a very similar shape to a Battenberg cake and almost as pleasant to the eye. It's a smooth, well rounded black cuboid with all buttons, switches and connectors flush to the device, giving it a futuristic feel.

The speakers are primarily designed to be used over Bluetooth – which means any device that supports A2DP and AVRCP profiles. In reality, this means your mobile phone or MP3 player.

Once paired, you can play the music from your phone using the two inbuilt 2 Watt speakers. You can even control playback using the touch buttons on the front of the device. The outside buttons control the volume, but double up as track skipping by holding the button down for a second. This makes skipping through tracks quickly an impossibility but does mean all your controls are in one place.

On the back of the device, you have a 3.5mm line-in jack – in case you're using a device that doesn't have Bluetooth. There is also a microphone, so you can use the speakers as a speaker phone.

Finally, what makes these speakers somewhat unique is the inclusion of a built in 1500mAh battery. This will last 8 hours at medium volume or 4 hours at maximum. Charging this can be done via the Mini-USB port on the back, or through the solar panel on the top.

Devotec quotes 12-24 hours to charge the battery through sun alone, but it goes without saying that in the British climate – your mileage may vary. Considerably.

The quality of the speakers isn't bad but there was obvious distortion when heading into loud volumes. Even in the medium volumes you could hear a small amount of buzz. With the speakers being on the end of the device, this means that they aren't facing you. This has the effect that the sound can be drowned out a little.

However, what is important is that the sound was well balanced and better than expected for the size. Where the speakers really shine, is when used as a speaker phone. Because of the long battery life, you can have it sitting on your desk, permanently connected to your mobile phone. When calls come in, it'll come through the speakers straight away. The sound quality is perfect for hearing voices and microphone is sensitive enough that the caller can hear you.

Included with the speaker set is a carry case, USB cable, 3.5mm jack cable and even a mains to USB cable to aid charging. For the £49.99 price tag, you expect these finishing touches.

Things aren't perfect with this device though. The microphone is built into the back of the device, which means having the back facing towards you for optimum sensitivity. This means you can't access the volume controls which are on the front.

Finally, we couldn't help but feel that a line out would have been really handy – but this is us being picky. That way, when not on the move, you could be using your Bluetooth phone to play music on your desktop speakers. Not every phone is lucky enough to have a 3.5mm jack, after all.

Price when reviewed:

The Devotec Solar Sound Bluetooth Speakers are well polished and offer adequate sound quality considering the size of the device. Battery life is excellent and will save on chewing through AA batteries. The solar panel is a bit of a gimmick, but it really shines through as an excellent desktop speaker phone device.

At £49.99 this is more than we would happily pay, but you do get a quality product that does its job well.