[anandhsub]

The battery of the key of my fluidic verna has so far lasted longer than the key itself. I had to change the outer shell of the key in 2018 because it had broken and boot open wasnt working but I continue to use the same battery that it came with in 2014.

[ashokabs]

I had two Honda City cars - one second generation and one third generation. In both the battery worked for over 10 years for sure. I think the 3rd generation had a CR 1620 battery and the 2nd generation had a CR2032. I think the key fobs are not waterproof in most cases. I know the 2nd generation one gave trouble as the car cleaner dropped it on water which had accumulated on the ground during rain. I hope the current ones are all waterproof. Incidentally the cost of the battery replacement is a factor of over 10 if you buy from Honda Service. Even in my little Tiago I have not replaced the battery in the past 6 years. I don't even know which one is required!!

[IP_Man]

My story.

Battery for my main key fob lasted for four years. I did not bothered much about it because I have spare key fob and I was under impression that car can be unlocked manually by dead battery in key fob because ECU can read RFID tag as it is passive.

One day, battery died. I tried to unlock car manually. Suddenly car started honking loudly and all turn indicator started flashing. It was embarrassing situation because everybody around me started looking at me suspiciously. Fortunately I was in my society, my wife brought spare key fob to rescue me from the situation.

Moral of the story, keep battery in the key fob updated.

[Transmission]

Originally Posted by MT_Hyderabad

Learnings: Expiry date on key fob batteries are exceptionally well calculated. Please keep a tab on it.

It will be better if you change the battery proactively, if it is reaching the expiry date. The spare battery may die at the same time, even if it is an unused sealed-pack.

Just wanted to highlight that the expiry date on the battery is for quality control purposes (and even then not exactly a hard date like the expiry date, say on a regular plastic milk packet) - and does not depend on the usage - in fact it assumes 0 usage.

In other words your keyfob battery will last longer or shorter depending on how much you use it - the expiry date on the battery has not much to do with it once you start using it. Of course, chances are that it will not last that long - provided the original dates were accurate. If you are more interested, you should look into the standby current of the keyfob and the capacity and the self-discharge rates of the specific battery it uses.

[TheBigV]

My Car Honda City 2015. My car uses CR 2032 batteries. The original Keyfob batteries lasted a total of 6 years 6 months, close to 85000 kms. Excellent battery life, to say the least

[MT_Hyderabad]

Originally Posted by absingh911

Out of curiosity, why is the battery health monitoring really needed? All cars in my family till now (key based ignition as well as keyless), have survived several years without any issues and you can lock/unlock as well as start the car even without a battery in key-fob.

Punto - 11+ years and going strong,
Dzire - 6+ years and no issues
Tucson - Just 2 years so lets see

The remote is a more of a convenience and less of a critical part. If it fails, your long drive still goes smoothly I think

No, in my case, I have to unlock using the key fob only, otherwise immobiliser kicks in and you cannot start the car. Secondly, the alarm, when you try to open using the key alone is mind blowing. I live on 5th floor and car is parked in basement. If the cleaner opens the car using the key alone, or he forgets to close a door properly, the hooter in the Safari wakes up everyone

Originally Posted by Transmission

Just wanted to highlight that the expiry date on the battery is for quality control purposes (and even then not exactly a hard date like the expiry date, say on a regular plastic milk packet) - and does not depend on the usage - in fact it assumes 0 usage.

This was my assumption also. I work in a pharmaceutical company, we can use the drug substance or any excipient even 1 month before the expiry date and the drug product (medicine) can have its own shelf life of let's say 3 years.
However, my experience with keyfob battery is different. They just started dying left right and center when the expiry month reached. May be it is a one off case, but worth exploring further.
My experience with car batteries with 44 month, 36 month shelf life is same. If you use a battery after 3 months of its manufacturing date, it will never give you complete 44 month service mentioned on the battery. Even manufactures have started recommending that you should not install a battery if it was unused for 3 months, even if it is seal packed. I don't remember where I read it.

[sudhirjaipur]

I have XUV700 purchased a couple of months, the remote key uses CR2032 battery, I am yet to know the life of this battery.

[Samfromindia]

My Ecosport one still working on factory battery after 8Yr / 1L Km driving. Lets see how more it lasts !

[PhoenixInRising]

This is my first post after my membership got approved. Today morning I saw this thread in the homepage which directly relates to my predicament.

We have an i10 Magna. Both the key fobs come with a pair of Lithium CR2016, 3V batteries. I was happily using one of them and the other one was lying idle. One fine morning while leaving for office I tried to unlock the car but the key fob was not working as the batteries have died. I tried to unlock the car with the key and the car buzzer started blaring and indicators started flashing. Luckily I was at home and used the second remote to stop the noise before my neighbours realised. The first key fob’s batteries lasted for 8 years after which I started using the second one.
Two days back I noticed that the glow of the LeD of the second key fob has reduced, signalling that time has come to stock up.

I have made it a point to buy 2 pairs of these batteries first thing tomorrow. I do not want a repetition of the above mentioned incident.

Thanks.

[anshu1101]

Not sure which battery was used in the key fob of my Vento. The batteries in both the key fobs lasted for 9 years until I sold the car, and never had to replace them. I used to use both the fobs interchangeably every few months.

[Nishith]

I can completely relate to this thread because I faced this issue on 2 of my cars within a span of few months.

The car that put me in the stickier situation is a not so modern 6 years old beater car that we use for the city run arounds a (pre-owned) Celerio VXI -AMT, since this car dint come with factory fit remote locking/unlocking, I had installed an aftermarket Xenos remote locking/unlocking system when we purchased it 3 years ago.

It has been 3 years after installing the remote lock/unlocking system and everything was fine.
One fine evening we had been to our relatives place, locked as usual (dint have to try multiple times) and we walked away as the car had to be parked 2 lanes away.

We decided to leave at around 11:30PM and it was raining heavily, managed to reach to the car with an umbrella and the car wouldn't unlock and I noticed the LED on the remote not lighting up, I was very sure that not even a drop of water had fallen on the remote due to rain and concluded that the remote battery had died. The spare key was at home, 18KM away and there was no one at home either.

So thought for a minute, unlocked the door with the key and opened the door. The siren started blazing along with the hazard lights, immediately opened the bonnet and saw if I can disconnect the siren. Oh boy!, I was so glad when I saw the fuse connecting the siren, I immediately disconnected it and disabled the siren. Jumped into the car, fired it, went to my relative's place (2 lanes away), picked my family and managed to drive back home slowly on the left most lane since, the hazard lights were still on.

Reached home, locked & unlocked the car with the spare remote and it was all fine.

Got the batteries in the spare key and daily use key replaced the very next day and its been working as expected so far.

PS: Since this car is mostly used by wife or dad, I don't know if they noticed issues such as drop in range or taking multiple attempts to lock/unlock the car. I am glad I was put in this situation as it would have become complex if this had happened when my wife or dad would have had to tackle it.

My experience with my XUV500 has been different, the car comes with the push button start feature and a couple of months back the ICE displayed an alert that the key fob battery is low and I immediately switched over to my spare key and replaced the batteries in both the fobs the same week.

So I think the modern cars do throw an alert when the key fob batteries are failing.

[mathewspaul]

Just last week, I replaced the battery in my Nexon's key fob for the first time. It lasted exactly 2 years. The key gave plenty of indications of low battery for a few days(not locking unlocking the car unless key very near to vehicle) and one day it completely died. Thankfully, the car was parked at home at that time. I changed to the spare key and replaced the battery in the primary one. After going through this forum, I am going to keep a spare battery in car for the peace of mind.

[stringbh]

I haven't changed my Vento's (at 1.45L km now) key fob batteries yet from 2013. Both keys have been used equally though. What is going on ?!

[GeeTee TSI]

I feel somewhere one should distinguish between key fob with and without keyless entry feature. The battery life in keyless entry fobs are expected to be significantly lesser in comparison

Not only is it a fussy procedure to unlock the door through the lock cylinder, it also complicates the push button start with the dreaded 'key not detected' error message. One can only hope to catch the low key fob battery message in time to not get locked out

[Aravind_M92]

Mine's a '16 city with keyless entry. Both fobs use a CR2032 batteries. Lot of options available. I've changed the batteries myself and have roughly changed the batteries 3 times in both fobs over the 6 years of driving. I use both of them equally. And I believe Duracell lasts longer as advertised. The OEM gave Panasonic at time of purchase and had used maxell for 2 replacements