Reference the D3200 manual:
In the cautions on page X, it states "Batteries are prone to leakage when fully discharged".
In the battery care instructions on page 185, it notes that the camera will draw on the battery, and should be removed if storing for extended time. But it also says to run it flat before storing the battery, which contradicts the caution on page X.
Nikons online care article echos the info on page 185, so I'm guessing the info on page X is leftover from earlier battery technology.
Having looked at all this, there are issues with Li-ion batteries. Some if not all have circuitry to prevent bad things from happening; think grounded aircraft and exploding laptops. I can't remember if there was ever a recall on older types of batteries, so that tells me Li-ions need more thought to use.