Key fob battery...

TLDR:
Purchase and carry a spare

$19 CR2450 Lithium Battery, 3v ECR2450, 12 PK

CR2450 battery in your truck...and if you use a AJT Designs fob case, make sure you have the appropriate allen key/wrench inside as well!

So,
Camping for a week in the middle of (almost) nowhere...well, as much as that's actually possible in the great Tri-state area, and on night 3 of 7 I go to lock my truck at night, just for the hell of it really.
Press the remote button and nothing... Get a little closer to the truck, nothing. Get inside and it starts, so I'm thinking it was a fluke of some sort.
Next day everything's fine. That same night I'm curious again so I hit the remote to lock - nothing. Get close, nothing. Get inside and try to start the truck - "key not detected" message on the dash!" message.
Great :/
I'm at a state campground, few ppl around but no one at the "office." We're about 15miles from nearest highway, then another 15+ min ride to nearest town with a store that might have a battery for me (which by now I suspected was the culprit).
Figure "eff it, will deal with it in the AM."
Get up the next day and luckily the truck detects the fob and starts.
Drove straight to Wally World to pick up a replacement battery + spare.
(told my son to stay in the truck, running, in case they didn't have any)

Half way through the ordeal I'm thinking "great, I'm probably gonna have to rip my AJT case apart with a knife too, if I can't find a way to remove the 4 case screws..."
Thankfully, my bike tool had a hex bit that worked and got it apart.

Are these fobs notorious for seemingly short battery life?
Note:
Daytime temps were around 80, dropping to 55-60 at night (I imagine this is why it still worked when warmed up enough in AM/day, but got cold at night) Trucks only 1.5yrs old, and I surely don't remember having to change fob battery this quickly on previous vehicles (granted, not with this newest/biggest style).
Anyway, never fails, almost making me stranded (or begging for ride/etc) at the worst time/place.

Big thanks again to the Toyota engineering team for implementing 1000 other nagging checks and messages ("Would you like to take a break?" message on dash after driving straight for 3+hrs, LoL), yet unable or unwilling to somehow detect and alert to weak fob signal/battery.
-99

 

Yup, been there. Always keep spares and an Allen wrench.

when it happened to me the first time, I was on day one of a 5 day beach trip. battery still lasted a the whole trip even after I got the first message.

I've replaced my batteries about 3-4 times, I have since turned off my FOB when not in use. They seem to last longer for me now.

 

Has happened to me as well. As an fyi, if it’s dead, you can hold the fob up to the start button as you press it and it should register it. At least that’s how it’s worked on my past Toyota's.

 

The battery in a lot of key fob from factory doesn't have a very long life. I've replaced many key fob batteries on 2022 vehicles at my job across all brands.

But no need to worry about being stranded cause dead key fob battery. You can unlock the vehicle with the physical key and press the FOB against the start button to start the vehicle. From the owners manual that almost nobody reads cause its thick as hell:

 

RTFM to the rescue!
Thank you for pointing that out.

Good to know there's a work around.
-99

 

Page 490 of the owners manual on how to replace the battery.

 

I'm still on Page 1...

 

Some folks just don’t know how to Ctrl+F or use their mobile device to search specific words. Anytime I walk away from the truck after locking, I turn off the fob out of paranoia. Probably saves some power too, had the truck since 06/23 and no fob issues. Even went through the washer.

 

Good thread, just converted to a MESO fob and also ordered a 5 pack of extra batteries (Panasonic-same OEM type) so can have some at home and a couple (along with the supplied allen key) in the truck.

 

Yea ,me too truck 9....I just found out these trucks go backwards and everything......amazing what they can do today.

 

Storing batteries including lithium in a car is probably pointless. High heat during summer months kills the little battery. I replace batteries in all my key fobs every 2 years. Even with a dead key fob, I’m still able to unlock door and start. I had an ex call me at 2am stranded some where because her fob was dead on her beemer. I hauled my ass to help her. At the time I didn’t know about the hidden key and the magic of holding dead fob next to starter button. At that point I decided not to be like “Karen” or stupid ex and read the manual lol