Locking the D3 with battery disconnected
 

I am off on holiday soon, and maybe leaving the D3 parked up for three weeks at home.

Now my D3 has a small current drain, which means that if left for a week the battery is pretty low. Now I'll be leaving it for 3 weeks, so it will most likely go flat if left connected.

Does anyone know how (if its possible) to lock the car after disconnecting the battery.

I'll let you know I tried this 18 months ago and failed, and in the end left the key with a neighbour to start and tun the car for 1/2 hour or so every 5 days.

What I have tried that failed.

A)
Use MMI to disable the central locking on all doors and boot, except the drivers door.
Lock and unlock the car, then lock it again with the boot open.
Disconnect battery.
Great except now the alarm goes off.

B)
As A above, but this time leaving the car unlocked.
After disconnecting the battery, there is no way to lock the drivers door. The key can be used in the mechanical lock, to open a locked drivers door but not lock it.

Using A, all is fine except the alarm goes off.
Using B, all is fine except the drivers door remains unlocked and cannot be locked.

Anything in VCDS perhaps.

The car is kept outside, so hooking up a charger or similar is not really an option.

Or run a C-Tek Charger plugged in while you're away - put it in the boot and run an extension lead to the boot locked inside and running back to your house with no external connects or breaks. The CTEK charger will switch up itself on and off as need to keep the battery topped up just fine +++

Can you not lock the car as normal then pop the boot using the middle button on the key?

That should work - and the boot will be locked and require electricity to reopen anyway.
Hopefully it will subsequently open with the key in the hidden slot above the numberplate.
It might be worth testing and lubricating that first off.

whats causing the current drain, its not the 10 % jobby is it.

When I did all the work on my car I had the battery disconnected and needed it locked, and yes it's just a case of locking the car, I think with the boot open and disconnect battery then close the boot, iirc if you lock the car with the boot closed then open the boot and disconnect the battery the alarm will start to go off on its back up battery, it's one way or another, but you'll know it's wrong as as soon as the battery is taken off it'll trigger the alarm.

As mentioned above, make sure the key lock works first otherwise you'll be right up poop creak, it is fairly stiff and could do with a bit of lube just to help it along first of all.

Just for reference, I don't have a parasitic drain and my car can be parked for a month and still start fine, I do have a massive yuasa battery fired though but it holds charge for ages.

With one of my previous cars I didn't drive it often so found the battery almost dead when I wanted to use it. I ended up buying a solar trickle charger and it seemed to help. They usually plug into the cigarette lighter but some come with clamps to attach directly to the battery. Of course this wouldn't work so well if you keep the car garaged!

Failing all this, you could just replace the battery before you travel? I recently went away for 3 months and didn't drive the car in that time. Unlocked fine, was a bit rattly on start up and the brakes needed a few hard applications to clean all the sh!te off them but it was fine.

I didn't think the battery being old was the issue here though Ollie, just the fact that there is a drain issue ongoing which would do the same to a new one over time +++

How about pulling the fuses on the usual culprits for battery drain like the radio & cluster and then locking it up?

Or put the car in transport mode, but I don't know if the doors can be locked in transport mode you'd have to try it.