The summer is here, and that means plenty of uses for a massive external battery pack. Whether the entire family decides to stay out at the beach for a few hours longer than your over-powered smartphone can last or a particularly nasty hurricane decides to knock out power for a few days, you could use some extra juice to fall back on. That's why now's a good time to snatch up the RAVPower 5600mAh battery pack that's currently available from Amazon for only $19.99 with a coupon code.

RAVPower

This battery pack provides enough juice to charge newer smartphones completely up to two times. Older phones or budget models, with their smaller batteries, may even be able to eke out a third charge. Multiple devices can't charge at the same time, since there is only a single DC 5.3V 1A output, but that hasn't stopped the battery from averaging 4.3 out of 5 stars from 244 reviews.

The regular price is currently $29.99. To save $10.00 off the price of this device, purchase it from Amazon as usual and enter coupon code ZZEWKM9O at checkout. It's pretty straightforward, but more specific instructions are available.

RAVPower 5600mAh External Backup Battery Pack