I have a 2014 Flying Spur. It has the factory battery maintainer that connects via a magnetic plug on the outside of the trunk.
I plugged it in at the car and then plugged it in to the wall outlet. It now blinks between two red lights. What am I doing wrong or is it defective? I tried the maintainer from my Aston Martin and it seems to be working. Thanks for any help.

 

I'd clean contacts to eliminate the simplest problem first. Have you tried the Bentley charger on the Aston? They are both rebranded CTEK's and should give you an indication if both chargers are functioning the same.

 

I use the charger and get this issue once in a while. I unplug the power cord for 30 seconds and press the reset key for a couple of seconds. it works fine after that.
Hope that works for you

 

Had this happen on an older BCGT with the older plug in style, inside the trunk.. Was a 20A fuse on top of the battery, which wasn't listed anywhere in the owner's manual.