How to Change the Battery in a 2013 Ford Fusion Key Fob
Owners of other Ford or Lincoln vehicles such as the Focus, Fiesta, C-Max, Mustang, Escape, Transit Connect, Edge, Flex, Explorer, Expedition, Taurus, F-150, EcoSport, MKC, MKZ, MKS, MKX, MKT and the Navigator may also find these DIY instructions to be helpful.
A replacement coin cell (A.K.A. "button" or "watch") battery is part number CR2025.
They are available from various manufacturers such as Panasonic, Sony, Duracell, Engergizer and Maxell.
You will need two new CR2025 batteries.
The tools that you may need to access and replace the batteries include a coin and/or a flathead screwdriver.
Update - The owner of a 2013 Ford Fusion informed me that their fob was equipped with just one CR2032 battery.
If your key fob is equipped with a chrome silver release button and a "switchblade" style flip out metal ignition key, it most likely requires just one CR2032 battery.
If your key fob looks like the one shown on this page and does NOT have a swing out metal ignition key, it should require two CR2025 batteries. The newer style of fob shown on this page instead has the backup / emergency metal ignition key located inside the fob under the back cover.
Please check the old battery in your fob before making a purchase.
Slide in the switch to release the back cover.
Pull off the back cover and set it aside in a safe place.
Insert a coin, butter knife or a large flathead screwdriver in to the notch.
Gently pry apart the two halves of the fob.
Gently pry out the top battery with your finger nail or a small flathead screwdriver.
Under the top battery, you'll see a piece of round white plastic that separates the two batteries. It lists the part number as CR2025 and reminds you to "change both batteries".
Gently pop out the second battery with the flathead screwdriver.
The OEM original batteries in the fob for this 2014 Fusion were Panasonic CR2025 3 volt coin cells.
Close the plastic cover over the first battery in the bottom of the fob.
Install the second CR 2025 battery in to the top socket with the "-" side facing up towards you.
When I was attempting to re-assemble the key fob, the silver key ring loop on the bottom of the fob popped off.
Slide the silver plastic piece back in to place on the top half of the fob.
Gently snap the two halves back together.
If you removed the emergency / back up metal ignition key, re-insert it back in to place.
To test the new key fob battery, stand near your Fusion and press the "Unlock" or "Lock" buttons.
If the new battery is working properly, you should see the parking lights flash and hear the door locks opening or closing.
Be sure to record the battery change in your vehicle's service records.
For more, check out my other 2013-2020 Ford Fusion DIY Repair & Maintenance Guides.
How to Change the Battery in a 2013 Ford Fusion Key Fob
Source: https://www.paulstravelpictures.com/2013-2016-Ford-Fusion-Smart-Key-Fob-Battery-Replacement-Guide/