b3 Passat AAZ won't start after dead battery and alarm HELP!

[Henchman]

So just finished putting on the winters and going to head off to get a new battery for the winter.  Battery dies before engine catches, when I remove the key the factory alarm starts (did not know I even had one) .   Hook up booster cables, get one more try, battery still too dead.  Leave it a minute, this time when I try, radio and lights go dead when I turn to glow plugs, when I try to start, nothing!  All I hear when I turn the key to the glow plug position is a click from the module under the back seat.

Any ideas?  I have tried disconnecting the battery, to no avail.

Thanks!

Ian

[Henchman]

The module clicking in the back is 357 959 875 comfort control ecu for power windows it seems.

[Henchman]

Things are a little better.  I think it may have been low voltage issue. My start battery must be worse off than I thought.  It's now being charged by the worlds most inefficient battery charge (my 7.4l powered motor home!).

Ian