Got caught off guard by a dead battery in my Ghost this morning, anyone else deal with this?

I was heading out for an early meeting near Downtown Dubai today and my Ghost completely refused to turn over out of nowhere. No weak crank or warning lights prior, just a sudden black screen on the dash which completely threw off my morning schedule. I end up calling a buddy of mine who runs a transport business here in the UAE to ask if he knew a reliable mobile crew, and he dropped a link for batteryzoneuae.com/rolls-royce-battery-replacement saying they can send a tech directly to wherever the car is parked with the right AGM spec. I honestly had no idea these complex electrical systems could drain down so abruptly without giving a cluster notification first, especially with the hot garage temperatures we get around here. Has anyone here used a mobile service for their car instead of having it flatbedded to the agency, or is it better to just bite the bullet and pay the dealer premium for peace of mind?