Long term without starting car

[steve289]

what is the longest anyone has left their Mondeo without starting it at all?

As it is holiday time, we are considering leaving our car at the airport for around 20 days, but dont want to come back to a flat battery.

Early 2010 MB Mondeo, diesel & on the original battery, which is not showing any signs of dying soon (touch wood!), no starting issues etc.

Thanks.