Key Fob Battery
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Rookie
Joined: Sep 2006
Posts: 47
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From: IL
Key Fob Battery
Got my 2025 RX350 in July last year. Drove about 4000 miles so far. Got a message yesterday that the battery needs to be replaced. Have only used remote start twice. How long should the battery last? Had a 2008 RX350 for 17 years and replaced the battery about every 4 years..
Pit Crew
Joined: Jan 2011
Posts: 229
Likes: 110
From: IN
I just checked my one year old keyfob battery and the battery tested like it was 100%. I generally, out of an abundance of caution, change my RX fob battery every two years. Your dead fob battery in less than a year of service is rare.
Racer
Joined: Mar 2023
Posts: 1,594
Likes: 899
From: TX
Got my 2025 RX350 in July last year. Drove about 4000 miles so far. Got a message yesterday that the battery needs to be replaced. Have only used remote start twice. How long should the battery last? Had a 2008 RX350 for 17 years and replaced the battery about every 4 years..
Instructor
Joined: Jun 2023
Posts: 941
Likes: 506
From: NJ
Also, be aware that many batteries obtained via mail-order are counterfeit or cheaply made. I always buy at a brick-and-mortar store.
To stop the car & fob from 'talking' to each other, store it in a Faraday bag.
A friend had the same issue as the OP on a Honda, he hung the second FOB right near the car and when he needed it, it was dead as a door nail.
To stop the car & fob from 'talking' to each other, store it in a Faraday bag.
A friend had the same issue as the OP on a Honda, he hung the second FOB right near the car and when he needed it, it was dead as a door nail.
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Pole Position
Joined: Jan 2007
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From: fl
[QUOTE=Carbuff2;12065277]Also, be aware that many batteries obtained via mail-order are counterfeit or cheaply made. I always buy at a brick-and-mortar store.
To stop the car & fob from 'talking' to each other, store it in a Faraday bag.
I also use a Faraday bag in the house. If you're working around the vehicle & have the keys/fob with you, you can hold the lock button down & and hit the unlock twice. This kills the fob so it won't talk to the car. The door handle lights won't work, can't open the doors, etc. until you reactivate the fob by hitting any button on the fob.
To stop the car & fob from 'talking' to each other, store it in a Faraday bag.
I also use a Faraday bag in the house. If you're working around the vehicle & have the keys/fob with you, you can hold the lock button down & and hit the unlock twice. This kills the fob so it won't talk to the car. The door handle lights won't work, can't open the doors, etc. until you reactivate the fob by hitting any button on the fob.
Pit Crew
Joined: May 2016
Posts: 198
Likes: 114
From: SC
The Dealer replaces my battery as part of normal service. They probably charge me way too much but it gets done. I tend to put off things (like changing the home HVAC filters). I would probably allow it to go dead and get stranded in some deserted spot.
Lexus Test Driver
Joined: Jul 2017
Posts: 9,582
Likes: 3,407
From: NJ
you can still start the engine with a weak fob battery.
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