Currently, USBCELL is only available from a dedicated web site for £12.99 (inc VAT and delivery), which will get you two Nickel Metal Hydride (NiMH) USBCELLs. Looking at the pictures, it is possible I suppose that that the cap might prevent the battery being plugged in, particular when ports alongside are in use. All in all, charging the USBCELL to complete capacity takes about five hours.
-Rechargeable AA NiMH Battery 1.2v 1300mah
-NiMH - Nickel Metal Hyrdride
-Built in Intelligent Charger
-Charge by powered USB
-90%+ Charged after 5 Hours by powered USB
-Also can be charged in approved NiMH Chargers
Company co-founders Simon Daniel and Chris Wright expect to be shipping other sizes of batteries, including AAA, in the new year. Though these presented unique problems during design and manufacture - the diameter of a AAA battery is less than the width of a USB connector - this will be resolved by making the connector fold in on itself.