Android Suddenly Loses Battery After Pulled Off Charge

[Android Question]

When pulling my HTC One by AT&T off the charger, I see it at 100%. I turn off my phone and turn it on a second later and it suddenly drops to like 96%. I turn it off and on again in a matter of seconds and it drops to 94%. I do this again and it goes down to 92%. It finally stops going down at 92%. It dropped 8% in a matter of seconds! It's been doing this for a month or two now. I have noticed that when I check my phone battery while it's charging up, it goes from say, 92% and jumps to 100%. I know this because I see my phone at like 92% while charging and turn it off to let it reach 100% and in around a few minutes, it's already at 100% that quickly. Battery life is important to me and I want it to last a long time. Does anybody know why my phone does this? I use the original Micro USB charger to charge my HTC One.

 

[Rukbat]

1) If you want the battery to last a long time, charge it when it's down to 50% as often as you can.

2) Going from 92% to 100% in a few minutes isn't the real state of charge. Leave it in for another 2 hours from the point it jumps like that and see how quickly it drops to 92% when you take iit off the charger.

(The terminal voltage, which is what the phone is indicating, doesn't have a 100% linear relationship to the state of charge near the top. It jumps to 3.75 volts before the battery reaches full charge.)