A 20,000mAh battery can charge two phones twice, or a phone twice and a tablet once. Some power banks have enough juice to power laptops. Of course, a higher capacity often translates to a heavier ...

This human powered cell phone charger is a great example ... the generated energy can be transferred through the battery terminals to a connected device. So, he cut a USB charger cable in ...

[Brian Dipert] looked at what this means in a practical sense by tearing down a GaN phone charger ... at higher power levels than their silicon forebearers. Cracking into the charger required ...

Is your phone, tablet, or laptop typically in the battery red zone before the day's end? These portable chargers and power banks give you the most boost when you're out of juice. I’m a Mobile ...

Read more: Battery Brands Ranked From Worst To Best To understand how a solar panel phone charger works, you really just need ...

A hidden display lights up sharing how much battery power is left ... has pass-through charging and is smart enough to only charge your phone when needed. On a recent trip, where I knew I was ...