I have a Venue Pro 11, which is normally powered either by the internal battery or by the external power supply.  However, there are times when both the internal batter and external power is unavailable.  I'm looking for an external batter which will power the Venue Pro 11.  Everyone I've seen may be powerful enough to power a smart phone or non Windows tablets, but none that allow enough of a power draw.

Has anyone been able to power a Dell Venue Pro 11 with an external battery.