Newegg offers the IOGear GearPower 11,000mAh Portable Battery, model no. GMP10K, for an in-cart price of $34.99. This $10 mail-in rebate drops it to $24.99. With free shipping, that's tied with our April mention and the lowest total price we could find by $20. It works with iPhones, iPods, iPads, and most devices which plug into a USB or microUSB power source. Offer ends July 14.