Smart keys eating batteries

But it is possible that one of the buttons was stuck down due to accumulated "crud" that got disturbed when the case was removed and replaced to change the battery. It is also possible that the battery contacts in the FOB needed cleaning.

At any rate, I don't buy the story you got from the dealer.

 

...unless you've read the manual, and know how to lock, unlock, and start the car when the fob battery is dead.

 

I assume you have the spare wrapped in metal so that someone can't simply get in the car and drive off, and so that you don't get the "key in car" message when you get out of the car.

 

Its not a spare fob its a spare battery.

 

Yes I can unlock the car and get the spare battery. Finished... good to go. No need to lock the car or start the car with a dead battery.

 

oh, sorry to have misread you.

 

Weird, I had a low battery warning once a week ago and nothing since. I can see that battery is weak after 3 years, but is there some kind of advanced warning before constant warning?

 

Maybe but probably not.
HEED the first warning you get; it might be the last and only one.

 

Same here, but I've had the 2010 only 6 months.

 

Here's my data point. The display has been flashing low battery every time I power off the car since December. 5 months later, I'm at the point where I have to take the key out of my pocket and press it to the handle to unlock the car. I also have to hold the key fob to the start button to start the car. That's a year and a half since I bought the car, terrible battery life for a key fob. The message did flash randomly to more frequently to all the time. So it was a gradual degradation.

The spare works fine and I am using it now. I'm going to use the spare figuring I can spread the wear and tear. Besides batteries have an expiration date. Now I need to go buy a battery, I hate how they come in two packs and I only need 1.

 

2 batteries for $2.77 on Amazon with free shipping for a $30K car. I don't see the problem. Place the second battery in the glove compartment in case the fob battery goes dead while you are on a trip and don't have the second fob available.

 

That doesn't seem to far off from what many other people experience - I think mine lasted about 2 years, give or take. Are you perhaps comparing to previous experience with a fob that wasn't a smart key? A plain fob doesn't take any power at all, except when you press the button, so its batteries can last a very long time. The smart key is always on, listening for the car - when it hears the car searching for the key, it sends a reply back. It also sends many more signals to the car than a regular fob; with a regular fob, it sends one signal to unlock the car, and one signal to lock it - so each time you use the car, only two messages. With a smart key, it's communicating several times as you approach the car (e.g. to turn on the interior lights, unlock the door), then again when you start the car, and more when you lock it. Rather than once for each of these events, though, it's probably transmitting a couple signals per second.

So yeah, a year and a half is maybe on the short side of normal, depending on a lot of things. But it might just be because it had some crappy no-name battery, which might've already been a year old by the time you got it. (I don't actually know when the fob batteries get installed - are they with the car all the way from the factory, or does the dealer/port install them?)

There are also things that can make the battery wear down faster, like being near a cell phone or other electronic device, or being close to the car for a long time. In any case, as the previous person noted - buy some cheap replacements, and don't worry about a year and a half too much.

 

This is not your fathers key fob.

The original ones were active ONLY when a button was pushed.
Not so with the fancy new ones that function as a "key" too.
They are active the whole time you are near the car........like keeping a real key IN the ignition.

A year and a half probably is a reasonable life for "new style" FOB battery.

 

Good point, the more one drives, the more battery use. We should measure the fob life in miles and not years.

 

Mine is in the car except when I'm away from home an the car is parked. So its in the car well over 90% of the time. The dealer had it 9 months before I bought it but the fob was most likely in the car a very small amount of that time.