L322 electrical problems

hi all,
I have a 2007 Mk 3 L322 and the battery keeps going flat, I know the battery is fine and the alternator is charging I've tried disconnecting the phone unit but it still happens and there's nothing coming up on the fault menus in diagnostics. Has anyone experienced anything similar?
Thanks for any help in advance.

Hello we see this a lot in the US the navigation unit is very bad but draining the battery on the vehicle just got the BMW style navigation unit in the left rear quarter disconnected and put a bypass for the fiber optics and everything will be fine

I have a 2005 Range Rover HSE (L322).

Here is what happened to me and how I fixed it:

1. Battery was draining and dying.

2. My RR would go into failsafe mode (transmission)

I took my RR to a good friend (mechanic) who worked on transmissions. When he realized that the transmission was good he kept the car for a week.

3. Ran a diagnostic on the wiring in the RR and found that it was not properly grounded.

4. Fixed that issue.

5. Then attempted to see if there was some sort of “drain” going on with the battery. Couldn’t find anything significant.

6. He recommended I buy a better, stronger battery and not an “Auto Zone Special.”

For me, all the problems stemmed from a cheap battery and the wiring not properly grounded.

Chi guys thanks for the comments, I did try disconnecting the sat Nav in the rear fuse board compartment but it made no difference, I replace the battery with the one of my Landcruiser as this is heavy duty and known to be good, I now have spoken to a RR specialist mechanic and he is going to have it for a few days - on the plus side he said it should be quite easy to find as it happens every day? Although after 15 years of working on LRs he did say he has never had two electrical faults the same? And after speaking to him for some time he seems to know his stuff and appears to be reasonable with his pricing, he said that he will look at it while doing other jobs as everytime he does something on it, it takes 20 mins to go to sleep mode and appreciates I don't want to pay for him sitting there for 20 mins each time hence the reason it will be a couple of days. I have spent weeks pulling fuses and trying different things without success although earths I haven't tried?