Key Fob Battery Life

[forbin404]

After 21 months I finally got the dreaded Key Fob Battery change...

Funny thing? Both keys needed the battery changed. Both hang in the closet about 40 feet from the car. I only use 1 of them (Other is just in case)
Odd.

Well I dragged out my Amazon box full of CR2025 batteries and found out they were so old they degraded to 2.5V (Need 3) and the remotes refused to light up.
A quick trip to the 99c store and got a set of 3, and my remotes are alive again.

Still wonder why 1 key which I hardly ever use and the key I use a lot both needed new batteries.

Note : My app sent me a VHR (Vehicle History Report), I went on the website and it mentions (under a gray notice that I should buy Carnet) that my keys are malfunctioning....interesting.

I didn't see if someone mentioned in the previous 6 pages how to change it, but you need to swing out the 'key' put a screwdriver in the hole where the key was and pop out the back cover where the battery is. Then you need a little paperclip to pop the battery out.

 

[miimura]

I just changed the battery on one of our key fobs for the second time because the car was complaining. The cell voltage was 3.0V. The new battery I installed was 3.3V. We have had the car for almost 29 months.

 

[Kosta]

I just changed the battery on one of our key fobs for the second time because the car was complaining. The cell voltage was 3.0V. The new battery I installed was 3.3V. We have had the car for almost 29 months.

since the fob is always broadcasting ? signal for keyless entry proximity etc .. regardless of use , the batteries will drain off I am guessing ..

 

[GlennD]

I just changed the battery on one of our key fobs for the second time because the car was complaining. The cell voltage was 3.0V. The new battery I installed was 3.3V. We have had the car for almost 29 months.

It seems like 3V is not enough. I just changed out the battery and the old one measured 3.07V unloaded.

It is simple to change but it seems that the fob needs 3.3V. 3.07 is within the lithium =spec.

 

[forbin404]

I just changed the battery on one of our key fobs for the second time because the car was complaining. The cell voltage was 3.0V. The new battery I installed was 3.3V. We have had the car for almost 29 months.

It seems like 3V is not enough. I just changed out the battery and the old one measured 3.07V unloaded.

It is simple to change but it seems that the fob needs 3.3V. 3.07 is within the lithium =spec.

Batteries don't give a fixed voltage for their life, they give higher voltage when new and that value slowly goes down.
Battery potential is measured by the voltage they put out. So 3.3V is good and when it sees the voltage drop to say 3.00V, it knows the battery is almost dead.

And the keys shouldn't been broadcasting 'all the time' only when the car sends out a signal for the key to answer. Works sorta like those tags at stores for theft, those tags work a long time because they don't use their battery until it sees a signal.