So, my experience parallels some other people's situation. My 12vdc plug in the boot (trunk) is only connected to a power source when the ignition is on. Now, that being the case, I am having a difficult time understanding how it could charge either battery unless I re-wire it to be on all of the time. Given that situation, the only logical solution to me, seems to be to wire the tender directly to the "house battery" and hope for the best. I have tried to find a wiring diagram for a 2007 GTC that would depict the actual circuit but that does not seem doable. In any case, my plug is definitely not live unless the ignition is on.

 

OK, I finally get it. The reason for the confusion is simply that my 2007 GTC does not have the socket. I checked everywhere and it does not exist. The cars in the colonies might not have everything that the "old country" has! In the meantime, I have gone ahead and hooked it up to the battery on the left hand side of the car (house battery) and it is charging fine. While it would have been nice to have been able to charge both at the same time, this arrangement will work well for me.

I conjecture that Bentley saves some goodies for the crown and does not provide a charge port for us on this side of the pond!

Thanks for all of your help and the fantastic information.

 

I thought that it was the 12V (cigarette lighter) socket in the trunk that I was supposed to charge via, or that one of the lighter sockets inside the cab would work, but they are only hot when the ignition is on for me as well. It did work to charge the left side battery (LHD car) directly though, once I managed to get the trunk open after a depleted battery. I have not found a three pin charging socket in my trunk either.

 

I also have a 2005 GT i just purchased. Getting battery error message. What trickle charger does everyone recommend? And would you charge just the batter on driver side?