Wonky battery meter

[lorkp]

My iPhone shut itself down last night because of a "low battery". I plug it in this morning and as soon as it boots up, it has 39% in the battery meter. How do I fix this?

 

[fireshot91]

Charge it all the way up (100%), then let it run down (0%), and turn itself off, then charge it back to 100% again. That should re-calibrate your battery.