Things I've learned owning a Prius and 2 Camry's with Smart Key.
The battery is near impossible to find locally.
The battery is covered by the 3 year bumper to bumper warrantee.
Not sure if the extended warrantee covers the fob battery.
Now I just pop in to the dealership and they swap the battery for free in about 5 minutes.
YMMV

 

Amazon.com has them for $2.04 shipped price.

 

For me it was quite a coincidence that this thread was resurrected at this time.

About a month ago, with 31 months on my 2009 TCH, I saw my first warning. bringing the fob ca little nearer solved the immediate problem. Since then I have been "living on the edge," thinking that when I had some spare time I would shop around for the best battery price. (It never occurred to me that these batteries were covered by the warranty.) I figured that there was little risk of serious trouble since I could always open locked doors with the mechanical key and turn the car on by putting the fob right up to the start button. And there's a Radio Shack a short walk from the house and the office where I could buy the battery for $5.


Friday afternoon, when I was leaving the office for an appointment on the other side of town, the fob would not unlock the door. I opened the door with the mechanical key and then needed to put the fob up against the button to start the car. Leaving my appointment to return, the same routine worked fine. So, "no problem," right ?

On the drive back to the office, I hit a major traffic jam on Loop 610; so I decided to take the next exit and browse the Micro Center there. Leaving the micro Center, the fob again would not unlock the door. Worse, the key was still separated from the fob - AND I HAD LOCKED MY KEYS IN THE CAR !! ......&%##!&%##

Then I went back into the Micro Center to shop for the battery. They did not have a CR1632. They did, however, have a CR1616, which was the right voltage and diameter, but thinner. (It cost 75 cents.) I decided to give it a try. It was a loose fit, but with the circuit board out of the fob case, I was able to press the battery tightly into place with my thumb and unlock the door. Then holding the fob up to the button turned the car on as usual.

I must be living right. If I had been in a remote place when things went rotten, instead of a Micro Center parking lot, I would have had a serious problem. If It had been my wife that got stuck, there would have been a marital problem involved as well.

I then went to the Radio Shack and bought two of the $5 CR1632's.

So much for shopping around. I put one battery in my fob and one in my wife's. I packaged up the used, but still functional, battery from my wife's fob and put it in the glove box.

 

Then again, if you did what I did - start looking as soon as the first indication came, you could have had two batteries for $4. The batteries came the day my fob refused to open the trunk or the doors.

 

Good going ! You must be living even better than I.

 

I guess you don't value your time very much. I hope you weren't actually driving around town looking for the "best price" with the cost of fuel and all.

 

Good one , Schmidt !!!!!

Actually this was a very thought provoking comment, on both counts.

Re. the cost of the gas, it is unfortunately true that I give a lot more attention to the fact that I burn half as much gas shopping around town with this car than I would have in its predecessor that I do to the possibility of avoiding some of the trips altogether.

On this one, however, I was thinking of internet shopping on the internet. That brings me to the other point.

Re. the value of my time, I had been flogging myself for not getting the internet shopping done before the battery quit altogether, but now I'm actually reassured that an entire month went by before I found nothing better to do with an hour or so of my time than to try to save 4 or 5 bucks.

Thanks to Shcmidt for making my day.