iPhone 4 owners can now double their battery life with the latest version of the Mophie Juice Air Pack.
Priced £52 and available to buy now, the superslim, 0.2mm-thick gadget is designed specially for the iPhone 4 and houses a 1500mAh battery that boosts talktime to six hours over 3G and 12 hours over 2G.
Users can also expect 270 hours when the handset is in standby mode, a maximum of five hours of mobile web use over 3G networks and 36 hours of audio playback.
An LED battery status indictor is onboard and adding to its appeal to heavy users is that the lithium polymer battery incorporates 500 milliamps technology for fast charging.
According to Mophie, its new bit of kit also doubles as a virtual speaker box to improve sound quality and will protect the handset against bumps and scrapes.
Last month the accessories maker hit the headlines when it confirmed it has developed a case that enables users to pay for goods by simply swiping their handsets over a reader.