What battery does a Lincoln MKX key take?

Lincoln MKX key battery

2016–2018

How to change a smart key battery

Slide the release catch and pull out the emergency key blade.
Wrap the tip of a small flat screwdriver in tape or a cloth, put it in the slot the blade leaves and twist gently to part the case. Keep it off the circuit board and contacts.
Note which way up the old cell sits before you lift it out. It varies by key, so don't assume + is up.
Fit a new CR2450 the same way up, holding it by the edges. Leave any grease on the contacts.
Clip the case back together and test the buttons at the car. Most keys work straight away with no reprogramming.
Keep new and old cells away from children. A swallowed button battery can cause serious injury within two hours.

2011–2015

How to change a smart key battery

Slide the release catch and pull out the emergency key blade.
Wrap the tip of a small flat screwdriver in tape or a cloth, put it in the slot the blade leaves and twist gently to part the case. Keep it off the circuit board and contacts.
Note which way up the old cell sits before you lift it out. It varies by key, so don't assume + is up.
Fit a new CR2032 the same way up, holding it by the edges. Leave any grease on the contacts.
Clip the case back together and test the buttons at the car. Most keys work straight away with no reprogramming.
Keep new and old cells away from children. A swallowed button battery can cause serious injury within two hours.

Questions

2nd gen (2016–2018): CR2450 in the smart key. CD3 / U387 — 2011 refresh of the first-generation car (2011–2015): CR2032 in the smart key.