Key Fob dies in 3 - 4 weeks

Unfortunately, I'll admit upfront I really don't have an answer for you.

I'm assuming you only have 1 fob, so no basis for operational comparison, such as the battery in this fob dies every 3-4 weeks, BUT this fob works fine?

It's a speculative guess, but only a guess that it must be that your fob "thinks" it is communicating with your Prius almost constantly. But I have no idea whether that is a defect with your fob or some other unknown issue causing that reality.

Given the proximity of my vehicle to my dwelling, I store my fob a good distance from my Prius when I'm not driving. I have to grab it before I go. I don't keep it in my pocket constantly.

Some have suggested for other reasons that you store a fob in a metal box, or in a box lined with aluminum foil if one has a reason to try to hinder, stop or disrupt communication between the fob and vehicle. I've never had to do this.

I suppose you could replace the batteries one more time and try when not using your fob storing it a good distance away from the vehicle and/or in the manner described above. If it dies in another 3-4 weeks I think you could be pretty sure it was a defective fob. If you're not pretty sure now.

 

You say that the red light comes on, but you are replacing batteries. Does the fob stay within range of the car for long periods? If so, the car and fob will be sending pulses back and forth, and that can use up the battery in the fob more quickly, even though there is no red light blinking on the fob. If that is the case, try turning off the SKS when the car is not in use. Also, interference from cell phones and other radio sources can cause what you are seeing. Also, a low 12V battery in the car can cause intermittent problems of all sorts, so it is good to check it.

Do a search for "chicken dance" to see what is needed to get a new fob going. It is not recommended to get the eBay fobs, as there is no guarantee that they will work with the SKS.

 

Good point....if you have only one fob, get another one NOW. There is great trouble and expense at the dealer ahead if you lose the one you have. A spare from PC user ovni (also on eBay) is cheap.

 

Store the fob at least 14 feet away from the car.

If the battery is still draining, try turning off the SKS feature.

If the fob is close to the car, it will constantly communicate with the car and run the battery down.

Don't waste money of E Bay fobs. If you get a new one, buy it from Toyota and do the chicken dance found here on Prius Chat

How to Program a New Key Fob for Full SKS Functionality | PriusChat

 

[delete ... just beat by a better answer]

 

If you have a base model Prius that came with the black logo keyfob, then you won't have the SKS (Smart Key System). Please disregard the comment about turning off that system.

 

I would suggest you start a new thread. You may find you will need to post additional information to your question.

 

we have the same problem with the battery.
the diagnose is that my wife keep the fob in her purse with her iphone. oh well. it's the price for "smart" tech and convenience.

 

I have a 2010, and when I bought the car I put new batts in the fobs. One is stored in a key box in the house, and the second key fob, the one I use every day stays in the car overnight (garaged). three weeks in I'm getting the low key battery warning.... Which kinda sucks.... we have always been a family of "keeping keys in the car" hen they are garaged...

 

The fob has a black plastic body in all cases. If the Toyota logo on the fob has a chromed finish, then the fob is for the SKS. If the Toyota logo is just black, then the fob is for the non-SKS system.

If the car does not have SKS, then you don't have to worry about where the fob is stored.

It is unclear why the fob battery is wearing out so quickly, if the fob red LED indicator is normally off which shows that no buttons are stuck. Normally it will last for years.