The EC Technology 22,400mAh power bank has an average score of 4.4 out of 5 stars and normally goes for $38.99. Applying the code MV76HD9U at checkout, will bring the price down to $28.99. Kmashi 20,000 mAh. The Kmashi MP810 has a capacity of 20,000 mAh, weighs 450 grams, and features a bright azure glossy finish. Like the EC Technology model, this large battery should get you multiple charges for most smartphones and even tablets.