Why did my phone battery jump from 19% to 46% in a matter of seconds?

[AC Question]

I have an Lg k7 and i turned my phone off at 19% on a charger and when it turned to the charging screen it said i have 46%. It jumped 27% within a matter of seconds. Can someone please explain what happened?

 

[belodion]

Either the battery is faulty, or the battery status reporting is false.

 

[Rukbat]

It sounds like a dendrite, a chemically-caused short in the battery. It gets blown out almost as soon as you start charging. As Belodion said, you need a new battery. (Dendrites aren't covered under any warranty - yet.)