Why does my battery suddenly die?

[AC Question]

I've bought a new phone just a week ago, but last night the battery died while I was sleeping. The day before, my battery life would stay at 94% for almost 3 hours and hardly dropped at all. It was around 70% when I went to bed. All apps should have been closed.

When I woke up, I couldn't get my phone to boot up so I started recharging it. At first it would display the recharge in the same manner as when the phone was completely shut off. It showed the battery life at 54%. Afterwards, I booted up the phone and it displayed battery life at 14%.

When looking at the battery history, the life would be around 65% before plummeting to 0%

Notes: I'm currently studying in Japan. I am unaware of any warranty on the phone. The phone is mostly used for messaging and google maps.

 

[B. Diddy]

Welcome to Android Central! Which phone? The battery might be defective or failing. Can you try a different battery (if it's user-removable)?

It might also be a problem with the battery sensor software. Try charging up to 100%, then using it normally until it shuts down from low battery. Charge back up to 100% again, and repeat this cycle 3 times to recalibrate things. Does that help?