FOB Battery Change

How many of you change fob batteries on a regular basis? Thinking both cars 2017 time to do it. We do have manual key for one, and push start for the other. For the push start toyota we have a manual key to get into the car, if the battery in the fob is dead is it maybe rfid where the car will start?

On my moms car, you just hold the fob up to the push to start button, emblem facing the button.


I try to replace my key fob batteries every 2-2.5 years proactively.


Bought my 2009 Corolla used in 2011, haven’t changed the battery in either key yet. Bought my wife’s 2016 Tucson last year and AFAIK the keys in both fobs are original.

I’ve been trying to get on an annual schedule to change the fob batteries, the remote batteries, and the battery for the garage door key pad. Not going very well though since I can’t remember when I changed them. Maybe if I just did it all on New Years day when I do the smoke detectors it would work out, but that’s a lot of batteries. Actually the fob for the Acura gave me a warning message once when the battery was getting low. So I guess I should make a list of the batteries needed and stick it on the calendar for January. Remind me again in December.

When a key starts giving me issues, I change the batteries.


I haven’t changed the battery on my 02 Chrysler van FOB, ever. It still works fine.

My cars tell me when the battery is low, except my 1999 Durango, it has a regular key.

when my key is getting low, I get symptoms like remote not working from 25 feet away, or I have to move the fob around inside the car to start the engine.
Anyway, there is lots of notice, and anyway you have the key backup (it will allow you to start the engine–read manual).

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As long as you change the battery soon after you can start the car with a “dead” fob at least once. Hold up the side with the logo against the start button and push the start button when you get the green light. The owners manual will confirm which number you need but it’s probably available at most stores.

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Yeah there is a key hidden in the fob of my Acura but the problem is there is no place to insert a key to start the car. The key will just open the door. Now you got me a little concerned. Never thought of the car not starting with a dead fob. And sure we have two but the wife has one and I have one and they are not usually together.

The other day in my Pontiac I must have done something out of sequence because the doors didn’t unlock when I put t in park. Danged if I could find the unlock button and had to use the fob to unlock the doors. Yeah life was easier in 1959. Remember to lock the door you pushed the lock knob down then pressed the door button in and shut the door. Then sometimes you go $#^&&^, the keys are inside.

Edit: Checking the manual, it says if you get the low battery message, the start button will start blinking. Then you are supposed to put the fob against the start button and you have 10 seconds to step on the brake and push the start button. So who knows why or how button think I’ll just periodically replace the button. I don’t think the wife understood when I tried to explain it to her.

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I replace mine (as well as every other battery around the house to prevent accidental leakage) about every two years.

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I don’t replace any batteries proactively. My smoke detectors are wired in.

My smoke detectors are also hard-wired, so the batteries only serve as a backup in the event of a power outage. Because these alkaline batteries are almost never drained by the smoke detectors, they could potentially last for several years.

However, I do replace them every 2 years or so. When Costco has a sale on Duracell 9 volt batteries, I buy a package, and this gives me enough to replace all of the smoke detector batteries with one left over for other purposes.

Now that we’re off topic, yeah mine are hard wired too. Along with replacing the batteries once a year, it it a time to blow the things out to remove any spider webs or dust. Mine were only four years old and our neighbor called us when we were in Ohio, saying the alarm was going off. Fire fire fire, CO, CO, CO. He said no fire but worried about CO and wanted the fire dept to test. I said there is no source, don’t worry about it, false alarm, get out of my house. (No I really thanked him.) So I had to buy an $80 detector on the way home to make sure I was safe, which I was. Just bought all new ones. So blow the dust out and spider webs anyway.

I changed the battery on my Mustang’s smart key a few months ago. The car notified me that the battery in the key was low. On my old Mustang I changed the battery on the remote (separate from the key) about every 4 years (or thereabouts). My mom’s Mercedes key/fob seems to go through batteries much more quickly, they seem to need replacement every other year or so.

Proximity key batteries don’t last as long as keyless entry batteries, keyless entry batteries can last 10 years.

The Lexus maintenance schedule indicates to replace the Smart Key batteries every 15,000 miles, that may be an extreme precaution.

“Fob” is an ambiguous term, I have key fobs for my classic cars.

I don’t recall having needed to change the key fob battery in the six years I’ve had this car. But then I use the fob only to unlock the car door or trunk from outside the car. When exiting the car I still hit the manual door lock out of old habit. And when opening the trunk to unload anything I use the manual lever inside the car. And once in awhile I still use the key to unlock the drivers door to get in. Old habits die hard. :grin:

Key fobs have good uses and supposedly provide better security against car theft. But the huge increase in armed carjackings since it became more difficult to steal a car without the matching fob seems a greater danger, at least here in St. Louis, than having only the risk of a stolen car.

On the newer ones, anyway, you don’t have to follow it because the car will tell you when the battery is getting low.