Southwest Airlines will introduce a new policy requiring portable chargers to be visible when they're in use onboard.

Some research suggests that portable chargers might be the second-leading cause of battery fires on planes, only behind electronic cigarettes.

There is growing concern about lithium-ion battery fires on planes because the number of incidents continues to grow yearly.

Southwest says it will limit battery charging to devices that are easily visible, in case chargers catch fire.

If you're planning a summer vacation and intend on booking a flight with Southwest Airlines, take heed of a new rule ...

Passengers on Southwest Airlines flights will soon be required to keep their portable chargers in plain sight while using them because of concerns about the growing number of lithium battery fires.

Southwest announced the new policy that will go into effect May ... risks for UL Standards & Engagement and works with 37 airlines and battery manufacturers to minimize them.