Okay so I woke up around 11am today and knew I was going to go out in the afternoon so I immediately (literally the first thing I did after standing up) was to dock the Switch and Joy-Con, I didn't play or mess around with it until 4:30pm I took it out of the dock and turned it off (by holding the Power button in portable mode and selecting Power Modes--> Turn Off) it did display 100% console charged, so I put it in my case and got out of the house to visit some friends.

After I arrived, I turned on the Switch only to realize the battery suddenly went down to 63%.

Anyone else have any idea how this would happen? Should I get it replaced from where I bought it?

Update March 3, 2017:

I charged the unit+joycon in full via dock and started playing around 11:20pm at these settings:

Manually set it to 50% Brightness and turned Auto-Brightness set to "On"

Wifi connected

Airplane Mode Off

JoyCon attached

Basically its at the out of the box configuration with the difference of having the WiFi connected (Stock has it on but of course, not connected to anything).

I was kinda panicked when I saw the battery at 24% at around 12:21am and my 1% notification came around 1:20am, but to my SURPRISE the Switch went on to play through until it shut itself off at 2:43am.

I have tried Googling and it seems that a ton of people have the same problem, I was just relieved that at those settings I still got past the 3 hour mark Nintendo set for BOTW, I may however try different methods such as having it on tabletop mode hoping that the JoyCons not being attached to the console will result in a longer play time since people have been telling me that as long as the JoyCons are attached to the console, it will charge it self using the Switch's battery. (Still weird since I did charge them in full when I first posted my problem here)

Basically the battery % display is inaccurate as hell, but until Nintendo doesn't release a statement about it, I can't guarantee my retailer will replace my unit.