Draining battery

[FST4RD]

I'm almost fed up with my car... something is draining the battery on my car.
I thought I'll hook up a multimeter to the battery and pull fuses 1 at a time until I find the issue. Only fuse that made a difference was the one that provides constant power to the clock, radio and interior lights. I thought I'll pop the fuse anyway and see if it was the issue. Nope... still a problem.
This leaves only 1 candidate, the alarm.
I've since found out it's a Cyclops A502CH. I found the brain, it has 2 plugs, a big one with lots of black wires and a small one with a red, yellow, grey and black wire. I can pull the small plug and the car still goes, but pull the big one or both and the car wont work.
Is there a way I can disable the alarm to see if it is the issue?
Is there a way I can determine the alarm is definitely the issue?

[Bling]

What sort of draw is the multimeter showing when the car is off?

[FST4RD]

Unfortunately it was just a cheapy one I borrowed since mine went missing, so wasn't able to check the draw properly.
I've had the battery checked properly twice, and twice it came back 100% fine.
But it did start happening all of a sudden, as if something pooped itself.

[DeeCee]

What is the size of the battery (cca) and how old is it? Yes there is a current draw from after market alarm systems, so expect the battery to drain slowly over time, but it shouldn't be an issue of the car is left for a week or two without driving. And when i say driving, i'm talking about a good run, not a short trip down the shops.

More info required

[FST4RD]

Pretty sure it's 600cca. It's a fully sealed battery.
If the car is left for more than a day without being started, by the second day it's dead flat.
The car tends to only get used in the weekend, and yes it does get decent runs.

[FST4RD]

Oh and the battery is about 2-3 years old.
But it's had the proper testing 2 times and come back 100% both times. So I ruled out the battery.

[DeeCee]

In my experience sealed batteries need to be run regularly. Had exide orbitals and optimas fail because they are not in constant use. You may have to look at a float charger to keep the battery happy. Do you also have a large stereo system? They can also introduce a parasitic draw on batteries

[FST4RD]

Ok I will look into that.
Would it be better going to a cheaper lead acid if that's the case?

Still would like to rule out the alarm too.

[DeeCee]

Alarm will have a 0.05A draw or there abouts. Good thread here discussing current draw viewtopic.php?f=3&t=92673&p=955453&hilit=alarm+draw#p955453

The sealed lead acid shouldn't be an issue. I used to leave mine for a couple of weeks and it wasn't and issue, but it is a Kinetik battery which is rather unique and heavy duty.

TBH, trouble shooting the causes of flat batteries is a time consuming exercise. Unfortunately, I have found that the most common causes are alarms and stereos (though most say that stereos won't make a difference as they are 'turned off' - they still draw a miniscule amount of electricity). Otherwise the battery is poked.

To isolate your alarm, you would have to know the wiring diagram and isolate it by disconnecting from the battery and reconnecting the immobilisation points, commonly ignition/fuel pump/starter motor so you can use the car without the alarm stopping the car from starting.