JasonAndreas

Can you temporarily disconnect your aftermarket alarm and sound system? Without them you should have no more than a 26mA current draw (16mA if you have a MY94).

DarrylH

The operative word here is should - but since it isn't, there may be a couple of things to look at.
1. Double check the data. 80 mA will draw the battery down, but not that fast.
2. Check the luggage compartment switch. Are you doing all these measurements with the compartment lid up? What happens when it's down (or at least, when you manually depress the switch?)
3. The battery sounds OK by the numbers, but maybe its wiring to the starter or its ground or power cables are a bit dodgy, so that on anything but a fully charged battery the starter's not getting enough current. Is the starter engaging when the battery is down? Or maybe it's been drained one too many times and just can't take it any more.
4. After you park the car and turn it off, stick your head under the dash near the CCU, you should hear the little temp sensor fan still running. It should go off automatically after about 15 or 20 minutes. Sometimes it just keeps going and going...For this to be the problem, it'd have to not restart when you disconnect the battery for the purposes of the test, but I dunno if that's how it works...FWIW

Lorenfb

A simple calculation:

Assume a standard 50Ahr battery, then for 1/2 capacity remaining for starting;

25 / (80ma) = 312 hr = 13 days

As I said, the battery will last about two weeks. Normal drain on a 964/993 is 40 ma.
If the CCU fails to shut-off the total draw will be over 120 ma. The 80 ma may result
from;
1. external alarm
2. booster amp
3. cell phone
4. other non-standard acessories