Immobiliser making the battery discharge.

[DogToothCheck]

Apologies in advance of this has been covered, have looked about but didn't find any specifics.
Basically, every time l alarm/immobilise the car the battery dies in about 30 mins.
I can leave the lights on, radio on etc etc and all is fine.
Unfortunately my skills are purely mechanical.

Any thoughts on how l put this right?

 

[DogToothCheck]

Solved.

Despite a battery of reading of 12.7v yesterday it's now decided it's only got 10.2
Binned and replaced with a honest, law abiding unit.
Thanks for looking.

 

[mty12345]

Despite a battery of reading of 12.7v yesterday it's now decided it's only got 10.2
Binned and replaced with a honest, law abiding unit.
Thanks for looking.

So to clarify for future reference, it was the battery that you replaced or the immo unit?

 

[DogToothCheck]

It was the battery giving sporadic readings. Never come across one that's done that before.
I celebrated by running out of petrol, oops..

 

[mty12345]

I celebrated by running out of petrol, oops..

Lol, never fun, might want to change fuel filter now, as can often fill up wth crap from the bottom of the tank if the fuel runs right out.

 

[DogToothCheck]

It's on the truly jaw dropping list of stuff to do.
At least there's no bodywork problems, just everything that's attached to it