dreaded battery drain

[chris62]

hi guys, i have the dreaded battery drain, i have a 2007 s type xs 2.7d, its been fine for the eleven months ive owned the vehicle, but suddenly the battery was flat when i went to use the car, charged battery and started fine, left outside locked and armed that night and dead in the morning, thought the battey may have dead cell so purchased a new batterry which was fitted to the car fully charged and was dead within two hours!!!  when i say dead i mean absolutely dead, nothing, no lights no ignition lights no power anywhere, had all electrics checked, all fuses pulled and monitored, and diagnostics plugged in and checked with nothing found, i now have to disconnect the battery after use, ( used every day) i forgot to disconnect yesterday, went out to disconnect an hour later but it was to late, it had drained the battery totaly, ive watched to see if anything becomes live after ive left it but nothing being reactivated that i can see, i am at a total loss  as to what is going on as is the electricians, can anyone shed any light on this?

[Nick2]

I had a similar problem with a yacht and the problem was the alternator.  The alternator diodes can fail and allow current to pass when everything is switched off.   Replacement alternator fixed it.  Just an idea, and slightly surprised that it is being drained in an hour.

[JOE-DOT-COM]

Hi

I had a battery drain, ended up been a tracker hidden in the boot, oe Jaguar, no idea it had one fitted, but it had a small house alarm type battery, which had gone duff and was draining the main battery

cheers

Joe

[dattrike]

My 2007 2.7 diesel had the same problem, battery going flat very quickly, just got it back from the garage, the problem was the glow plug relay unit sticking on, new relay unit fitted by garage all ok now, (£57 for the unit).

[XylinaF]

I have a 2004 jag x type 3.0 and my battery light comes on when I'm driving which is usually an indicator that the alternator is failing. I tested the alternator it is fine, bought a new battery ($350) and still have issues with the battery . The car will be completely dead and a hour later start right up... Also have had a tracker on my car before unknowingly but I assumed it was retrieved...