Right Joy-Con 2 Battery Installation

Apply isopropyl alcohol to a cotton swab and wipe any adhesive residue from the frame.

Use an opening pick or your fingernail to lift the foam off the battery by its adhesive, not the foam itself.

Carefully peel the foam sticker off the old battery. Avoid stretching or tearing the foam.

Apply the foam sticker to the new battery so the edges of the foam are aligned with the edges of the battery.

If your replacement battery came with adhesive pre-installed, peel off any adhesive liners.

Align the battery with its housing. Ensure the battery cable lines up with its channel.

Lower one side of the battery, then the other, into its housing.

Press and hold on the battery for 10 seconds to bond the adhesive.

Check that the release pin sticks out of the controller when the release button is pressed. If it doesn't, or if the button fell out entirely, re-insert the button and try again.

Align the battery connector over its socket on the board.

Press down on the connector until it's fully seated.