For the first time since I bought the car, I got the "low key fob battery" warning in the dash. 5+ years that is impressive for a 2-way remote!

Oddball size though CR2450. I had to look up how to change it. I wonder if I should go ahead and replace the battery in my spare key? Do these type of batteries ever leak?

 

in my time at the ford dealer, i have never seen one leak. and IMO i would replace the other one as well. Thats what i would always recommend to customers

 

Never had one leak, but buying what I consider "fresh battery" from a good source is imperative. Ive bought "good deals" off of Amazon and eBay and they do not last. To answer your question: buy a 2 pack and change them both. JMO

 

I still have the original batteries in one of my fobs and it still works. I just started using it recently after the other fob case broke. I did get a replacement case for that fob and it will be my backup until I have problems with the one I'm now using.

The "CR" designates the battery as a round lithium cell. I've never heard of one of these leaking like an alkaline battery.

 

Mine had the same thing. Now i have an auto delivery from Amazon to ship me one every 6 months. The batteries aren't as good, but they will last a year, i replace each key every 6 months.

 

Bought the below 4 pack. Cheaper than 2 singles.

 

The 2450 lasted so long because it is much bigger than the common 2032. But being less common it is more expensive.

 

I've never had a key fob battery last less than 5 years, and they give a warning a couple different ways (range, dash message) a while before they go dead. The spares in my junk drawer advertise a shelf life of 10 years.

 

I think my previous F150 fob had 2 2032s in it. I replaced it at about 6 years, and even then it hadn't yet triggered a low battery warning, but I thought I perceived a little loss in range.

 

Where did you find the correct fob case?