Get this Original Sharper Image Universal Portable Charger/ Backup Battery for $10 after code SPECIALBRAD. Note that the code must be entered in the "promotion code" box after you begin to check out. With free shipping this is $15 off and is the lowest price we could find by $3. This backup battery comes with adapters to charge almost any mobile device. It is compact and comes with a travel pouch to make it more portable on trips and vacations. There is no sales tax (except CA).