https://electronics.woot.com/offers/anker-24-000mah-65w-portable-power-bank Anker 537 PowerCore 24,000mAh Power Bank w/ 65W Total Output (A1379) on sale for $34.99. Shipping is free for Amazon Prime Members (must login with your Amazon account and select a shipping address in order for Woot to apply free shipping) or is $6 per order.