Power banks are big rechargeable batteries with built-in USB ports, and their flexibility and portability make them one of the most useful accessories you can carry for keeping your devices topped up.

SAVE $52: As of Dec. 18, Anker Prime 20,000mAh portable charger is available for $77.99 ... That’s 40% off, making this deal too good to pass up. Let’s start with the specs that make this ...

All products featured here are independently selected by our editors and writers. If you buy something through links on our site, Mashable may earn an affiliate commission. Credit: Mashable Photo ...

New Anker wireless chargers ... may be able to stock the charger eventually. If you're after a new charger in the here and now, then check out our guide on the best portable chargers.