Cellboost is yet another option for giving your devices a quick recharge when you can't get to mains power.

The inexpensive batteries can transfer about an hour of talktime and 60 hours of standby to a mobile phone, and about 8 hours of audio playback to an iPod. Because they're designed as disposable cells, they come without cables or adapters, and plug straight into the device. It's not one size fits all – you have to buy the correct Cellboost model for your device.

You can use your device while it's charging with Cellboost, or give it a quick boost as its dying, and then save the Cellboost to use again in another session.

Because it contains no mercury, Cellboost can be disposed of in a regular dustbin. They range from £5 for a mobile phone Cellboost, to £7 for an iPod-compatible model.