Backup batteries are nothing new, but the $35.99 Extreme Boost 20,000mAh Backup Battery is not just a run-of-the-mill external battery pack. It adds overcharge, overcorrect and short circuit protection to keep your phone or tablet safe as it charges. The 20,000mAh capacity and four USB ports mean you can charge multiple devices at the same time.
![](/wp-content/uploads/archive/C122F1A2-54CE-4D28-93A3-9AE24BB18FE0.jpg)
![](/wp-content/uploads/archive/C122F1A2-54CE-4D28-93A3-9AE24BB18FE0.jpg)
- Charge up to 4 devices at the same time
- Smart Charge Technology automatically adjusts charging speed to your device
- Power up safely w/ overcharge, overcurrent & short circuit protection
- Get multiple charges w/ a huge 20,000mAh capacity
- Monitor charging progress w/ the LED charge indicator
It’s available in both black and silver, and your purchase today guarantees that you’ll have it in hand by late July.