Why does my iPhone keep shutting down and says it has low power?

[iMore Question]

My iPhone 5 keeps on shutting down whenever I use it unplugged and there were times where it keeps saying it has low power even though I charged it to 100%, so I charge it all over again. This occurs with or without a SIM card inserted. This annoyed me, and I went ahead to reset the iPhone to its factory settings. Still not working. Tell me, is it a hardware problem or software problem? And can you give me tips on how to fix it?

 

[metllicamilitia]

Sounds like a battery issue. Lithium-ion batteries lose overall capacity over time. The iPhone 5 was released in 2012 so after five years the battery capacity could be fairly well worn out. The best thing to do is either have your battery replaced or upgrade your phone. Should the issue persist if you replace the battery then I would recommend setting up a Genius Bar appointment at an Apple Store and discussing the issue with them.