I understand the backup battery only last a few years before failing, sometimes taking out the PCB with it which causes lots of grief.

Anyone ever replaced the battery?

What's involved?

I stripped an alarm down to see. As the original was a sealed unit had to cut carefully round the seam with a hacksaw before prising apart, but it had rotted the pcb , decided it was not worth fixing , replaced with a s/hand unit but it only lasted a few months . Didn't bother with it again.

I found the thread below about replacing the batteries, but this is for the Fabia II which may have a different alarm to the Octavia Ii. The alarm location is also different.

http://www.briskoda.net/forums/topic/321205-does-anyone-know-where-the-alarm-siren-is-on-a-2010-fabia-2/?p=3865825

Thanks for the info, just to expand...

Were there any problems that prompted you to take a look? Maybe prompt action could save a total loss scenario.

Where is alarm located/access?

Did battery look replaceable?

The alarm is located above the drivers side front wheel arch behind the wheel arch liner which you'll need to remove to get access. From memory it is held in place by a nut/bolt and a pop rivet.

The alarm siren is a sealed unit and is not designed to be taken apart. When it failed on my octavia the signs it was faulty (other than a vcds scan) were random alarm activations and the drivers door led stopped flashing. The alarm activation beep also stopped happening.

Unless it's faulty I'd leave it alone.

The replacement cost is now circa £130. :(

Presumably the (dis)arm beep is a feature you can change in VCDS as mine only flashes the indicators.

Thanks for all the info, good to know for when things start playing up.

I'm sure there's another thing that has a limited lifespan... airbags?

Damn modern cars, just made to be used and recycled.

Re the alarm set beep, yes I should have been clearer - it isn't enabled by default on all cars. You can turn it on in the maxidot menu if you have one or otherwise can be configured as you say with vcds.

EddieNL pointed out in the other alarm thread that has popped up today a good way of checking the alarm siren:

http://www.briskoda.net/forums/topic/323808-vrs-alarm-questions/

yes

a good way to test is by locking the car, then open it with the keyblade (not remote) after about 20 seconds the alarm will go off

Airbags now last for the life of the car.