Smart Key Battery Replacement

Seahorse · Aug 6, 2013

So I got a warning about low battery today and bought a set of Duracell CR2032 batteries from Argos for £3.99. I have changed the battery, re-assembled and it doesn't work i.e. pushing lock or unlock buttons does nothing. I have also popped it in the slot and the car will start. I have had it in bits about 5 times now and can't see what the problem is. The + sign on the battery is away from the small circuit board.

Any tips or suggestions?

wilf · Aug 6, 2013

If the battery is correctly seated, I might suspect a duff one......

How long was the fob without a battery in it? I seem to recall they lose their programming if the battery is out for longer than a set time?

Colin11 · Aug 6, 2013

Think the Side touch on the battery can be iffy

Did it on mine when I changed battery ..... seem to remember having to bend it a bit.

Cj10jeeper · Aug 6, 2013

You should be ok with new Duracell. I had issues with non branded batteries still showing as needing changing.

Can only suggest try your old battery again so you know your fitting it correctly and connections made. Then try the new / another battery.

Seahorse · Aug 6, 2013

If I hold the battery against the terminals it works, so I assume the side prongs are the problem. Commence bending...:asa:

Seahorse · Aug 6, 2013

Bending up or down seems to have no effect. Popping some folder paper behind battery to raise it also fails...

wilf · Aug 6, 2013

is it meant to be a 2032 or a 2033? The latter is much thicker, but the same dia.

TheStig · Aug 6, 2013

It's a 2032

...20mm diameter, 3.2mm thick.

Seahorse · Aug 6, 2013

2032s, the prongs. I have tried bending the left on in the picture, up and down and the same for the two tiny arms on it to no avail.

Spursmaddave · Aug 6, 2013

The key I have been ysing is running low I think as occasionally the dash says not present but I haven't had a battery warning?

Seahorse · Aug 6, 2013

Big red letters between main clocks appeared this morning for me.

Spursmaddave · Aug 6, 2013

Probably soon to come then as I say couple of times it has said no key present and a couple of times I have gone to open the car and it wouldn't so battery low is my guess.... swapped to my 2nd key and all good but wan't to replace the other one rather than risk having neither 100%

jerryjal · Aug 6, 2013

Edit: ignore me I'm blind!

wilf · Aug 6, 2013

I recall now that I had a couple of "cheapy" new batteries not work in my old car's fob.

Seahorse · Aug 6, 2013

These are Duracells and they work if I pin them by hand, just not when fob is reassembled...

Popped the wife's fob open to play spot the difference, hers is in the rear. The side contact is at 90 degrees, mine is almost flat. One screwdriver twist later, two working fobs...:knuddel:

MyIRRCat · Aug 6, 2013

Good spot, the second contact has to make contact with the outside of the battery.

richmond · Jan 24, 2014

I just replaced the battery in one of my smart key fobs. All went well until while reassembling the side clips I noticed the end of a small spring sticking out of the side. With a sinking heart I realised that it must be the spring for the key release button which was nowhere to be seen. I spent the next ten minutes crawling all over the floor and the desk looking and feeling for it.
Eventually I went back and had a closer look at the fob and realised that the button is on the other end of the spring which just needed reseating properly before putting the whole thing together and putting the side clips back on. Whew, what a relief. Apart from that fiasco it's an easy enough job.

J500 · Jan 14, 2015

I know this is an old thread, but I came across it whilst looking for a solution to a 'Low Battery in Key Fob' warning issue I've been having.

When I bought my car at the end of Nov, it had this message on one of the keys, I changed the battery but had it again about a 10 days ago, changed the battery again, but two days ago I had it again. Now granted I'm using cheap batteries, but wondered if there might be another cause. Having read this thread, I bent the side contact so as to make a more positive contact with the battery and Hey Presto, the 'low battery' is working again and has been for two days or so since. This suggests a poor contact can also trigger a 'Low Battery in Key Fob' warning which might be worth trying if anybody has the same issue.

J500

Bethpage · Jan 14, 2015

I find that if the key fob gets really cold, especially this time of year, it can trigger the Smart Key Battery Low warning

Dave · Dec 29, 2016

Coincidently I've been ooop norrrfff with hard frosts and hey presto my low battery warnings is on

GeoffW · Jan 14, 2015

Using quality batteries from a reputable source is the solution I've found. There are many fake proprietary brands around from ebay, Amazon etc.

ivanov · Jan 26, 2015

I've just had my first 'Low battery in key fob' warning. Got home, grabbed the other key (which I've never used in 2 years) and tried it out. It ALSO had the same warning. This puzzled me - I would have thought that the spare key would have had more life in it, but I know that both batteries (Panasonic) were fitted to the fobs when new, so perhaps the current drain is the same, regardless of use.

Anyway - I set to work and pulled them both apart: defluffed and cleaned both, and gave a little nudge to the contacts. And remembered to keep the key release button aligned on reassembly.

Went out to the car with one key - no warning. Then took the working key fob back inside the house, and swapped it for the other one - it worked without warning as well.

This has me puzzled. However, I'll pop out and buy a couple of spare batteries just in case.

FIXIT · Feb 9, 2015

The last couple of days I've had a puzzling problem with my key fobs. The batteries were replaced about 3 months ago, and I tend to alternate the use of each one.

I've had no 'low battery warning' but using the fob to lock/unlock the car takes 2 or 3 attempts, pressing the buttons quite hard. This would usually indicate a low battery or connection problem with the tactile switches underneath, but a quick visual check doesn't reveal anything obvious. When it does decide to work, it still operates at a decent range. The keyless entry fails to work, but never had a problem once in the car with starting or when travelling. Any ideas anybody?

Gav · Feb 9, 2015

The only thing I can suggest John is the battery contacts. Make sure they're clean and the battery sits snug in them.

FIXIT · Feb 10, 2015

First thing I tried. However, this morning I went out to test them and they both worked fine, which leads me to suspect the receiver end. The battery wasn't particularly low but it did go on it's weekly trickle charge from the C-TEK overnight. Coincidence?

ivanov · Feb 10, 2015

...and both of my keys now need new batteries. Odd how they both went at the same time. No matter - bought two new ones and all is good again.

Ricfx · Feb 19, 2015

Changed both mine last week and all OK, Lucky or what.

FIXIT · Feb 19, 2015

Both my key fobs are behaving now. Batteries are genuine Varta and have been installed since October.

JayF · Dec 29, 2016

Just replaced both of my smart key batteries.

Ridiculously easy.

I wonder how much a main dealer would charge?

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dslives · Dec 29, 2016

£27

*i figured they'd do it as a courtesy when I dropped if he XFR for a full service!!!!!!!! yessir. Did the other myself in 30seconds with a total outlay of about one quid.

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Ben · Dec 29, 2016

Do people really take them to dealers to change the battery? It's described in the manual how to do it!

JayF · Dec 29, 2016

I bet plenty do.

RTFM! Perish the thought. 😉

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JayF · Dec 29, 2016

I'm surprised they don't wear a mask as that is daylight robbery.

It took me no more than 30 seconds per key and the batteries are a couple of quid in Tesco.

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Smart Key Battery Replacement

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