Anything is possible, I got 3 flip keys with the car and the valet key which does sound like a lot of keys? I definitely used the flip key.

I am still confused though, if there are definitely no deadlocks on the boot, and its purely mechanical, why would a flip key or any other mechanical key work after starter battery was removed, but not work after battery failure? Surely the conditions are identical?

Maybe I just didn't try hard enough to turn it, Lol that would be hilarious. I could swear I tried two or three times.

Lol. That would be amusing +++

That's a lot of keys... Are they all identical? Or is one different, and specific to the boot for example?

The lock is mechanical, and should turn both ways, anti clock to lock and disable the central locking iirc, middle for normal operation, and turn clockwise and push in to open....

Isn't it the opposite way to that Ian? Not that it matters much as it's easy to verify...

Definitely anticlockwise and push to open mine. Just tried it. ;)
Maybe one of them has a "valet" type of blade; IIRC that will not go into the boot or glovebox, only the door and ignition.

I have to look at these keys more closely, they all look the same at a casual look, but I never examined them closely.

I want to re-create the same conditions but with the battery outside the car with some long leads. Hopefully it was just me not trying hard enough :ROFL:

wouldn't the drill hole behind rear number plate unlock boot with the fine screwdriver be easier ?

Try all 3 keys in the boot first would be easier still. ;)

When leaving my car for long periods I always disconnect the battery and lock/unlock the boot manually using the key. My key also unlocks the drivers door manually when battery is disconnected.
The only time I found your problem was when I used the wrong key :Confused:

Yup definitely have to try this.
Confusing thing is, the same key did not work on the boot when it was electronically locked, and the very same key worked on the boot after I took the starter battery out.
If it was the 'wrong' key it would not have worked on the boot at all.

So either something fishy is going on or I just did not try to turn it hard enough anti clockwise after the battery failed. As I mentioned earlier the same key turned the lock as smooth and easy as anything with no battery in the car.

Unless there's something about the power boot release that "jams" with low voltage, but if you look how the mechanism works that's not really plausible - unless something is broken......

I'm thinking of doing this as our plans this year mean the S8 could spend several weeks at a time with no running.
Based on previous experience of dead/swapped battery the only thing you need to do is enter the RNS code again.

However I have two questions:
1. Are there any particular precautions to take re locking/unlocking the boot or anything else?
2. Has anyone ever used one of the battery isolator gadgets that typically seem to have a screw clamp to open and close the earth-side circuit?