TheTokRa

The batteries I was using were both supplied in the same twin pack though, genuine Duracell packaging. 1 lasted a year, the other seemingly DOA. Weird!!

Bummer!! They must have changed the cell to a 2032 for a longer life span.

LOL!! I know exactly where you are coming from my friend. I work in IT too 😉 Sorry it's been a while since I replied. Do you remember I said the car was going in for is MOT and a service. Ummm, it failed for the disks and pads being too heavily scored, so I had to replace those, and the windscreen wipers. So with that work done and the service and MOT cost as well, I'm £700 down, BOOO!! I was thinking of changing the car soon, but having forked out £700 on it, I'll be keeping it a bit longer now LOL!!

Thanks Scot5, I'll have a look at those two vids shortly. You can say "I told you so" if you like!! LOL!!

Hey guys, so TLDR, Yup!! This was a bad battery! Was at work this moring and found a JCB branded cheapo CR2025 battery to try in the fob, Voltage read as 3.31v no load and no warning on the dash to say low battery anymore. I will try to get some better branded cells when I go to the shops this evening. Still flabergasted that a new Duracell battery that reads as 3.27v under no load can be dead under load. That's nuts!!

The spare keyfob battery is also around 3.0v and showing as needing replaced. I'm sure it would work in the fob I use every day, but it would not resolve the issue.

That's a fair point guys, but surely the IR would need to be considerably higher on the new battery for the voltage to drop more on the new battery with an open voltage of 3.27v compared to the old battery with a open voltage of 3.0v? As I said, I think these batteries were from the same twin blister pack, bought about a year ago I think, Does the IR in coin cells tend to increase if the cells are not used at all? What value of resistive load would be comparable to the load of the fob? I have some resistors laying around I could use to test.

I will buy some more new CR2025 batteries next time at the shops, See what happernsd with some other new batteries, but while not 100% accurate, multi-meters do not lie, if a battery consistently reads as 3.27v and the other battery that needs replaced reads as 3.0v that seems pretty accurate to me I may have some CR2025's at work, but I'm not back in till Thursday.

Was going to ask the same thing 👍

Yes, you are 100% correct, but as I mentioned in my first post, I did clean the battery with Alcohol in case of that very issue.

Ah, right, so the alarm only goes off for a short period of time while you put the key in the ignition. OK, well, at leas that gets you motoring again. Thanks!

Very odd!! I'd still suspect a dodgy connection in the extension somewhere. Loose wire at the plug, at the sockets end, or a damaged conductor inside the insulation.

Correct me if I'm wrong, but if the car was locked with the alarm set (by keyfob) then if you open the door with the key like in this video, won't you set off the alarm? I'm sure I was another video to that affect a while back.

OK so this issue is really driving me nuts now. Found the spare keyfob, took the battery out, it's also on it's way out at 3.01v so I put the new battery in that, and the LED blinks when I press a button. Great I thought, but nope, althoughh the LED blinks when I press a button on the fob, the car does not resopnd to the button presses. I put the old battery back in again, and keyfod works fine again. repeated this process serveral time in a a row with the same results. How can changing a the battery, that reads as being 3.27v AND makes the LED blink when buttons are pressed, not open the freaking car doors????? Apparently the fob only work if the battery is low! WTF!!

Watch this video. You can skip the first minute of the clip, it's just BS.

Hi Scot5, Thanks for your reply. As I said, I have check the voltage of the cells, and the old battery is 3.0v the new one is 3.27v so it can't be a dud. The batteries were probably bought at the same time (I think) and are from the same two pack blister pack. The pack states that the cells should be good till 2026. I have swapped the battery from new to old and back again about a dozen times now (making sure the battery is in the corect orientation) with the same result every time. I'll dig out my spare keyfob and try the battery from that in it. Just seems really odd, the battery contacts are fine, no issues there.

Good morning everyone, So I have a weird issue with my key fob. I am getting the "replace key fob battery" warning on the dash, so I had a new spare Duracell CR2025 battery still sealed in the packet. I took it out and replaced the battery, but the fob would not work at all, no blink from the LED when I press a button on the fob. So I took the new battery back out and put the old one (also a Duracell CR2025) back in, and the fob works fine again, still low battery warning though. I measured the voltage with a multi-meter, and the old batteries voltage reads as 3.0 v. The new batteries voltage reads as 3.27v so it should work just fine, but every single time I put the new Duracell battery in, the fob stops working. I have cleaned the new CR2025 with alcohol in case there was some sort of contamination causing a contact issue, but it still does not work. Anybody got any ideas? Thanks!!