Hi I have purchased another RR a gorgeous , although bit posh SDV8 diesel autobiography.
My former 2012 L322 Westminster SDV8 ,which gave good service , Dash melted , the dash cooling fan failed (£100 part )with build up of dust or age , and the main dash melted . Took 5 months to eventually source a new old stock dash at £700 on eBay rather than £2600 from LR if available on back order . So clean behind the dash if you have one or replace the fan .
Any how my new RR is losing charge down to 12:1 volts after standing three days. I have checked battery , which at 7yrs old has lasted well and TOPDON battery tester says to replace . My question is how long will the car stand before battery flattens? If we leave at the airport for two weeks after fitting a new battery , will it still start or do I need to take my jump
leads?

Less than a week for mine and I get the 'Please start engine' message. Also the tailgate won't open. It has never failed to start......yet and it has both brand new batteries.

Mines a gen 1 2017 and I’ve regularly left it for 2 weeks on my drive and it started fine.

I have a DIY tracker on mine that I bought off Ebay. It's obviously powered up all the time and I sometimes wonder if that is much of a drain. If I disconnect it to prove my point that is undoubtedly the time that the car will get nicked.🙄