Until the Chargeboxes that Pocket-lint reported on months ago become ubiquitous, running out of battery on portable devices is a daily hazard for most people. Two battery packs, one from APC and one from Motorola, may give you piece of mind.

APC’s Mobile Power Pack is a small backup battery no bigger than a deck of cards that is compatible with most portable devices, include media players and mobile phones.

The company claims that its lithium polymer battery cells have a higher power density than traditional li-ion cells and are thus more compact. The Mobile Power Pack stores enough charge for up to 55 hours of music playback from an iPod nano, and 8-10 hours of usage time for smartphones.

The device is bundled with an AC to USB power adaptor and a USB to MiniB power cable, and is available for £45.

Motorola’s offering, the P790 power charger, plugs into a mobile phone or Bluetooth headset’s mini-USB port to provide two full recharges for handsets, or more than ten for headsets.