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Get this Refurbished T-Mobile Universal Micro-USB Portable Battery Pack for $9.95 at All4Celluar. Shipping is $2. This is lowest price we found as compared to a new one by $5. This 1950 mAh battery backup can charge most devices that use Micro USB as their charging port. A long list of compatible products can be found under the specs tab on the product page. It's available in black or red. There's no sales tax (except IL).