Why is my battery draining and gaining very quickly?

[Notfluffy]

Updated (Lumia Cinemagraph Beta, Glance Screen, and Vieather) and installed (Order & Chaos Online and Gestures Beta) some apps today, and noticed some battery issues. Like earlier my phone said Critical Battery, even though it was fully charged 30mins ago and did nothing to it, so I went to charged it. Immediately, it says 100%. It's probably the 3rd time it happened today. Is there a reason behind this? a bug perhaps?

 

[Oliverspin]

Possibly, it could be the way you are charging your phone. I still can't find a definitive answer anywhere, but I've read some places that overcharging your phone, keeping it plugged in too long, can have an adverse effect on your battery. Additionally, odd charging patterns, such as charging from 10% to 30% all the time instead of 30% to 100% can also harm the battery life. Another weird concept is that if you have an odd charging pattern like that, it will trick the battery into treating another percent as 100, in other words, and my friends iPhone seems to do this, the phone can last a REALLY long time on low battery because it is essentially showing the wrong percent of battery. I'm not sure about all that though.