What's the biggest battery you can fit in a Gen.4?

My old 70 series LandCruiser was fitted with the winter pack and that included two 110 amp batteries which were wired in parallel. Nothing fancy just two big batteries.
Modern cars use the lightest items that will do the job and that includes thin wires and small batteries. I charge Vivs Audi once a month and ditto Tonka. I use a Ctek charger which gives the battery what it wants without overcharging it. You can leave it connected full time if you so wish. Having to replace the battery that often is probably down to the belief that the system is infallible. Trust me/us, it isn't. Buy a Ctek or equivalent and sleep easier.
It was George in Australia who had a lot of the problems associated with flat battery and alternators switching off.
I am fitting a bigger capacity battery when the store re-opens. Think of it as a bigger fuel tank, you don't need it most of time but when you do, you've got it.

Roger

Two weeks sounds a bit quick, but if it wasn’t used for 2 weeks, it’s only 100mA/hr to sap 33Ahr in two weeks, so might take a little finding. My Gen3 is less than half that and I have a Bluetooth battery monitor on which takes a few mA.

Have you fitted anything that is powered all of the time, camera, tracker, etc?

Robin

Went to the dealer today after getting jumpstart and battery test(FAILED) from my friend. I have just a dashcam and the normal radio/media dashboard setup.

The battery I am using is Motolite MSFN60L.
Dealer did not allow access to their workshop. It might as well go into a black hole in my opinion. Anyway, it was a busy day and I was rather late. Managed to get the battery replaced because jumpstart did not work at all at the dealer. Maybe I will leave it with the dealer when I go for a long  break in future. 
I still feel something is wrong somewhere. 
These intelligent electronics gets on my nerves.


 

So it's killing the battery not just flattening it? I have a very deep mistrust of dealership service departments especially if they don't have viewing facilities. If it were me I would be marking the battery in a way that I could identify if they have replaced it or just charged it. I would also be looking for an alternative professional garage to get a second opinion, even a motor factor with a battery condition tester like Halfords or German and Swedish could check it and even change it for a small fee. I just can't get my head around how leaving the car alone for a fortnight is writing off the battery? My land cruiser will flatten it's battery if I leave it too long but it's just flat not ruined needing a replacement.

I just recalled one of my goner battery was because I was careless to leave my headlights overnight. 

Thinking back, maybe it should be a case that a jumpstart can resolve instead of replacing the battery.

Unless there's something absolutely catastrophically wrong with the rest of the electrical system, which would be abundantly obvious to even the most newly qualified dealer workshop tech, leaving the lights on is never going to destroy a battery, it will simply need a recharge.