Why is my battery life stuffing up?

[iMore Question]

Why is my battery life stuffing up

i have recently got an iphone 5 of my mate and i would charge it to 100 and then when i took it off charge it would drop to 70 in 5 min with me barly using it.... it also at times turns of at 50% and then when i try turn it back on it says it needs to be charged and then when i turn it back on and put it on charge it says 49% PLEASE HELP ME

 

[Bigeric23]

Re: Why is my battery life stuffing up

Did you set it up as a new device?

https://support.apple.com/en-us/HT204686

 

[Just_Me_D]

Re: Why is my battery life stuffing up

Make a Genius Bar appointment with the nearest Apple Store to have them diagnose the problem for you.