If you want to charge your Nintendo Switch JoyCons while playing you'll have to shell out $30 for a charging grip.
A bit of bad news regarding the Nintendo Switch's fancy new JoyCon controllers. While playing the console in portable mode, with the controllers connected to each side of the tablet unit, will charge them, if you are playing the game in TV mode with the JoyCon's connected to the grip that comes bundled with the unit, will not. You'll have to go ahead and shell out $30 for the official charging grip if you want to play and charge at the same time.
Essentially, the basic JoyCon grip included with the console is simply a plastic shell with no additional features. It's the same as simply holding one JoyCon controller in each hand.
Nintendo's official site lists the Joy-Con's battery life as "about 20 hours", although notes this may become shorter with use over time. The two Joy-Con take 3.5 hours to charge - whether attached to the Switch itself or the premium Joy-Con charging grip accessory.
Something to consider when purchasing the console.