One of the biggest questions we still have about the Nintendo Switch concerns its fancy new peripheral, the Joy-Con. These detachable, tiny controllers have a variety of features baked in, but just how long do they last for? While we weren’t able to get a concrete answer on its battery life, Polygon did learn just how to keep the controllers juiced up during Nintendo’s hands-on press event with the Switch.

There are three methods of charging the Joy-Con. The simplest way to refresh the controllers’ batteries is by attaching them to a docked Switch. Inside of the dock, which ships with the console, is a USB-C connection that the tablet slides right onto. That will keep both the Switch and the Joy-Con charged up for on-the-go play.

When it’s not in the dock, the Switch can be plugged in with the accompanying USB-C charging cable that’s also included with the standard package. That will again send power to both the console and its controllers, assuming the system is in handheld mode with the Joy-Cons still attached to either side of the screen. The controllers will also charge as long as they’re hooked up to the Switch unit, even if the device isn’t plugged into power itself.

If the Joy-Con are removed from the Switch, they can be charged with the Charging Grip. That also has a USB-C connection, and plugging the cable into the Grip, which is sold separately for $29.99, will charge those controllers up.

What we’ve grasped thus far is that battery isn’t a huge concern for these controllers, however; the controllers had been repeatedly left to run on battery alone during the media event we attended, and they had yet to require a charge. They’ll last for 20 hours on a full charge, according to Nintendo.

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Still, what we’re not yet sure of is just how to tell when these controllers need to be plugged back in to charge. There are lights on the inside of each controller and the face of the charing grip to signify if they’re synced to the system and, if so, which player they belong to. If the Joy-Con straps are in use, however, these lights are covered up. If the Joy-Cons are attached to a Switch that’s in handheld mode but not plugged in, the interface is also obscured. Perhaps there’s some functionality built into the tablet’s operating system?

We still have a lot to learn about these new peripherals, including just how their batteries work. The long story short of it is that we wouldn’t expect to have to worry about these rechargeable gamepads going dead all too often, however.

Correction: Joy-Con controllers will charge as long as they’re attached to a Switch unit, even if the Switch isn’t plugged into power itself — they draw power from the Switch’s built-in battery, Nintendo said during a Treehouse livestream on Friday. We’ve edited the article to reflect this and to add the Joy-Con battery life.