Key Fob Battery Only Lasts 6-8 Weeks

Key Fob Battery Only Lasts 6-8 Weeks

The battery on my key fob for 2013 model S85 only lasts about 6-8 weeks before I start having trouble with doors not responding to press on the handle or even having trouble when I click the fob. I have tested new batteries in both fobs (3.3 volts when I put them in) but they just don't last. Fobs are new as they were replaced by Tesla a year ago when they found a problem with the antenna and replaced it). Even the battery in the new Tesla fob (supplied by Tesla) only lasted 8 weeks. When I was still having problems, they tested again and couldn't find any further issues. When batteries no longer work they still read about 3 volts. I am out of ideas. Is this normal? Several times I have had to find the spot on the windshield to put the fob when battery wouldn't function and I was out of cell range. Solutions?


ALSET | November 27, 2019

That doesn't sound normal but I don't know what the problem or solution could be. Bought my S back in May and I'm still on the same battery for the FOB and it's working well. I hope I didn't just jinx it.

MS-2013-60 | November 27, 2019

Purchased my car over a year ago no problem with FOB.

bobrobert | November 27, 2019

Better than mine on a 2014 S85. After 5 years 1 fob suddenly started draining its battery within 10 days. I've taken it to SC twice, and now, 1 week after last "repair" it doesn't work at all, even with a fresh battery. Grrr

tes-s | November 27, 2019

Do you get a fob battery warning on the dash?

My battery lasts about a year - but even when they are still working, I get the warning on the dash which is annoying. No way to turn it off. I like to wait until the battery is DEAD before spending 2 minutes and $1.50 replacing it. :)

I think I replaced the battery in the other fob once in six years. It is rarely used or near the car.

Ohmster | November 27, 2019

How far from your car is your FOB when you park for extended periods (like in the garage)? We had to move my key further away from the X and (in a Metal box) as it kept unlocking the doors while it sat there. That’s got a be a drain on the batteries.

‘17 S75 + ‘17 X75D Both: Uncorked [E]AP MCU1 FSD AP2.5 Intrusion Grin on!

Stoaty | November 27, 2019

No fob warning on the dash, just starts having trouble unlocking doors after 6-8 weeks. Fob is in condo on second floor, below that is first floor and below that underground parking garage. I keep one of the fobs in a metal can, haven't been doing that for the other.

regoapps | November 28, 2019

This happened to me years ago. Did your key ever get wet? Maybe someone in your family did the laundry and forgot to take the key fob out? My guess is that something in the circuit is shorting and running the batteries down. The only solution I found was to replace them.

jordanrichard | November 28, 2019

My FOB battery is almost 2 years old, no issues.

NKYTA | November 28, 2019


Stoaty | November 30, 2019

Fob never got wet. I am using new fobs provided (free) by Tesla when they replaced the antenna about a year ago. Both fobs have the same problem. Very annoying.

spineeric | November 30, 2019

I can imagine how annoying this issue is. People on this forum can usually determine the issue, or at least someone else has experienced a similar issue and point you to a resolution. So thinking aloud.....

Have you owned this car since new? Is there a setting in one of the menus where the car continuously sends a signal to you? Also possible that a neighbor in the condo is using a device on the same frequency as the car/fob??? Since one of your fobs is in a can, the other is not, but both display the same 6-8 weeks life span, there has to be something in your building interfering. Just a thought.

Are you using a key fob holder/sleeve that might be continuously pressing on one of the buttons on the fob?

Stoaty | November 30, 2019

I purchased the car used from Tesla 2.5 years ago. It is a 2013 S85. I have Energy Saving on and Always Connected on. I should clarify that the capacity loss for the fobs is when each is used and not in the can. I have switched them to see if there is any difference. Both came with a little rubber "jacket" and attached key ring. I am going to try taking that jacket off to see if it makes a difference (don't think so, but who knows). My batteries were purchased from Amazon, test at 3.3 volts new and kept in refrigerator and are name brand. May try buying locally from a store to see if it makes a difference. Thanks for additional thoughts.

akikiki | November 30, 2019

If it were my car and fobs, I would first go to the SC and ask them to reprogram them to the car. Maybe that will fix it. Remember to take both, they must do both at the same time to sync them to both work on the car.

But I like regapps answer. Sounds like a fob - wet fob problem. But asking to reprogram them is free - most of the time. Before you buy a new fob.

Anthony J. Parisio | December 1, 2019

Another thing to try, remove the batteries and make sure the metal contacts are bent out enough to apply firm pressure. When it comes to these sorts of low every devices you would be surprised how much of a difference this can make. I had an ICE car in the past that gave me a similar problem. But first try removing the strap t see if the buttons are some how being pressed.

Stoaty | December 1, 2019

Why would you expect reprogramming the fobs to help given that they work fine for 6-8 weeks and then stop working? Again, thanks to all who contributed ideas. Hopefully I will find a solution eventually.

ALSET | December 1, 2019

Got the notice on the dash today that FOB battery was low. So I did jinx myself. Incidentally the FOB and battery are just over 6 months old (I bought my car during the last week of May).

PrescottRichard | December 2, 2019

If you are adventurous you could get a faraday bag for your fobs. Putting your fobs in the bag would stop them from communicating with the car. All that will tell you is if there’s some kind of over-communicating going on that drains the batteries.

barrykmd | December 2, 2019

Haven't read all the responses, so apologize in advance if this has already been mentioned...

Perhaps the fob is too close to the car, so it is constantly talking to the car and being drained.

My batteries were changed twice, pre-emptively - at 2 and 4 year service. Have never seen a low battery warning.

jordanrichard | December 2, 2019

2 days ago upon getting home, then plugging the car in I got the FOB low battery message. However, yesterday morning, and since then, the message has not appeared.