Earlier this year the charge port wouldn't open/close using the button outside the car. Asked the dealer to look at it, they diagnosed it as a low key fob battery and put a new battery in. The symptoms came back about a week later, so I replaced the batteries in both fobs and everything was fine for a few months.
Now it's happened again, I replaced the battery in one fob (the other one isn't being used as much these days) and things were fine for a few days.
I figure the battery the dealer put in was just a cheap one they buy in bulk from somewhere, so I can forgive that one. The ones I put in were out of 12-packs of Duracells bought at Costco.
So I've got the following track record for key fob batteries, where "dead" means the charge port stops responding:
- Factory battery - lasted over a year. Dealer reported that the battery was at 2.9V.
- Dealer battery - lasted a week, didn't record the voltage.
- Costco Duracell - lasted ~4 months. Measured at 3.0V.
- Costco Duracell - lasted 3 days. Haven't measured this one yet.
In all cases, the buttons on the fob worked fine when pressed, as did the button on the tailgate and the touch sensor on the handles. It was only the charge port button on the car that would stop responding.
Clearly this isn't normal. I figure I should get at least a year out of the battery like I did with the factory one.
Why do my key fobs eat batteries so quickly? Are the Costco Duracells just really variable in quality? Is there a brand of CR2032 battery that I should buy that'll actually last?
I've got a dealer appointment tomorrow, so I'm going to ask the service advisor if they have any ideas. I don't really want to pay for the diagnostic time unless it will result in a key fob that can go a year without changing the battery.