I noticed that my iPad Pro 10.5’s battery seems to be draining unusually fast the past two days somehow. After being fully charged 4 hours ago, it is already at 54% with 3 hrs total use. Is there an accurate app I can use to check the capacity before I take it in to an Apple Store to get its battery replaced? Which brings me to my next question, should it be at the same $20-ish that the other batteries are currently being replaced for if it comes to that?