Hola!

I just bought my 2015 CX-5 last Saturday, and I got an early as I was shutting the car off that my Key Battery is low.

Now granted, it's a 2015, so that could explain it, but should the fob be low that quickly?

If I replace the battery myself am I voiding some warranty, or should I just run it to the dealer and have them do it?

 

No change it yourself why go to the dealer if you are uncertain how to open the fob check your owners manual its in it.

 

Key fob battery life does vary from 1-3 years, so yours is on the short end. Nothing to be concerned about as there are lots of variables involved.

 

you are not voiding any warranty buy changing a battery. we change them in parts for customers all the time. just the cost of a CR2025 battery and we will install them for free all day. takes like 1 minute when you get the science down. haha

 

Went through this on my 20I4. Easy enough to do by yourself, even I, a mechanical klutz, could do it.