Tesla Model X Panasonic CR2354 Key Fob Battery
Panasonic brand CR2354 Lithium Coin Battery. Key Fob Batteries should be replaced once a year at your annual service. However if a Fob is placed to close to the proximity of the car it can prematurely kill the battery. Also if the Fob is stored in an excessively cold or hot place the battery can be drained. Don't get stranded without a functioning fob. This is especially critical if you park your car somewhere without cell coverage and cannot use the phone app to use as a back up.