cbdgro via eBay offers this 12,000mAh Dual-Port External Battery Pack in Black or White for $8.47 with free shipping. That's $2 under the lowest total price we could find for a similar item elsewhere. It features an LED indicator light and two USB ports.

Also available is this 20,000mAh Dual-Port External Battery Pack in Black or White for $13.57 with free shipping. That's also $2 under the best price for a similar charger elsewhere. It features the same specifications as the above model, but with more charging capacity.