Newegg offers the SCUD Panku 10,000mAh Power Bank External Battery Charger, model no. M-100, in Silver for $22.99. Apply coupon code "VCO" and checkout with Visa Checkout to drop the price to $20.69. With free shipping, that's $9 under our April mention and $39 below the lowest total price we could find elsewhere. It is compatible with most smartphones and tablets and can charge an iPhone four to five times, a Galaxy S4 three times, or an iPad Air once. It weighs 8.6 oz. and measures 5.8" x 2.3" x 0.6". Coupon expires August 25.

Note that the above coupon can only be used once per account.