If the portable power bank is intended properly it can't be over charged. Any good device that has Li battery within can have a correct charge controller for that individual Li particle battery. because the battery approaches its absolutely charged state current from the charging circuit can change posture to some extent wherever it's impossible to over charge the cells.

With our busy lives, it’s surely not impossible to stay watch your phone on every occasion you would like to charge it with an power bank. At some purpose, you’ll leave the phone connected to an power bank even when it’s full. Some people have asked within the comments whether or not a phone battery will ‘boil over’ thanks to an power bank charging too long. we tend to determined it absolutely was time to analyze whether or not or not it’s safe to depart a phone connected once it’s absolutely charged.

When a power bank overcharges it can do one of a few things

Decrease the Power Bank Lifespan

Electronics lifespans are continually decreasing. The batteries used in all electronic devices hold less charge when you recharge it. you'll ne'er have constant charging lifetime than the day you got it. this is often true for phones, laptops, tablets, and yes, power banks. If you permit your power bank obstructed in too long and it's no means of stopping the electricity from flowing into it, then the surplus electricity can injury the facility bank and it'll hold less and fewer of a charge over time. So, if you would like to form the most use out of your power bank, don't keep it obstructed in longer than it must.

Prematurely kill your Power Bank

Because the lifetime of your power bank are decreasing day when day if you overcharge it, eventually the lifetime are low enough, or there'll be enough damage done in to finally kill it off. Power Banks, like all electronics, don’t last forever. If you still damage your power bank as a result of you retain it obstructed in long night when night for too long, then it won’t last as long.

Explode

Most power banks don’t explode. The news stories you hear are of specific events and with typically lower quality power banks that were overcharged and left within the heat. it's an ideal storm that ends up in the power bank exploding.