The Anker 10000mAh external battery pack will charge our beloved TF101 because it is the only one that has a 9v or 12v output option on it. The battery pack comes with most of the connections but the only additional thing that you will need to purchase is a USB 3.0 F to F coupler.
Anker battery pack: http://www.amazon.com/Warranty-1000...F8&qid=1345071382&sr=8-1&keywords=anker+10000
USB 3.0 F to F coupler: http://www.amazon.com/gp/product/B00695L9BE/ref=oh_details_o02_s00_i00?tag=amaz98-20
Voila!!! I am using this battery pack to charge 4 different accessories without having to bring along 4 different wall adapters.
Anker battery pack: http://www.amazon.com/Warranty-1000...F8&qid=1345071382&sr=8-1&keywords=anker+10000
USB 3.0 F to F coupler: http://www.amazon.com/gp/product/B00695L9BE/ref=oh_details_o02_s00_i00?tag=amaz98-20
Voila!!! I am using this battery pack to charge 4 different accessories without having to bring along 4 different wall adapters.