What's the mitsubishi lancer key battery size?

All Mitsubishi vehicles with a key fob battery, including the Lancer, use CR1620 flat batteries, which You can pick up from just about any major outlet. They're sometimes referred to as "watch" batteries, and they're made from many different manufacturers like Panasonic, Energizer, GE, Duracell, Maxlel, and Sony. If You do a quick Amazon search for CR1620, You should be able to find some options for under $1 per battery. More reputable manufacturers' products may cost a bit more -- You might be looking at $3 or $4 per battery. Though it's inexpensive, I've found it's something that gets put off -- at least in my own experience. Do YourseLFA favor and pick one up. The swap isn't hard, and shouldn't take You more than 5 or 10 minutes once You find the motivation.