Mophie have today released a new version of the Juice Pack, designed specifically for the HTC One, the case for which has been designed specifically to provide complete device protection without sacrificing the phones zero-gap unibody design.
The pack claims to be able to double the battery life off the HTC One after a single charge, providing 100% extra power via its 2500mAh rechargeable lithium polymer battery.
This can all be done on demand, by flicking a simple toggle switch from standby to charge mode.
You can even sync the phone whilst the case is fitted to the device, via the pass-through USB port, and the device also includes a four-light LED status indicator to display the amount of charge available.
The juice pack for the HTC One is available today in both black and silver for $99.95 from mophie.com and various other retailers in the US.
No news yet on the UK however.