Hey I need some help I have a 2012 Bentley mulsanne and I left for a month and didn’t plug in the trickle charger the car starts and drives fine but when using the remote key to unlock the doors none of the electronics work I don’t get welcome lights when the door is open and also when I turn the car off I see lights flickering The a/c controls the Cruise control light and they stay on for an hour while the car is off the alarm goes off when I open the door manually I been reading online that the “LH” battery is going flat and causes an engine light seems to be my exact problem is a I don’t know what and LH battery is is that something I can buy my self and install my self or is it something I would. Need Bentley to do I called to get a price and it’s pretty expensive they quoted me at 1800 to replace the LH battery if there’s no other options I’ll obviously take it to Bentley to have in installed if. There’s no other options that’s for your help in advance

is it also to late to plug in the trickle charger I’ve been charging it since 4 hours with no luck I can unlock with the key once then the tail lights fade and the button doesn’t work no more while being on the trickle charger

 

Hello @ginogordos ,
Welcome to 6speedonline !

As far as your issue with batteries, if the Mulsanne is anything like the GT or FS, then you you have the left side house battery and the right side starter battery, as far as the $1800.00 to install just the LH battery, that is absurd, I have installed both batteries in my GT, I went with the platinum batteries as shown in the link below, roughly $200.00 each.
If you post some pictures of both sides of your trunk area with the covers removed, we can then help you to replace said battery or batteries.

https://shop.advanceautoparts.com/we...&storeId=10151


Johnny

 

As Johnny said about if being the same as a Continental GT.
I would also add that there are probably so many error codes on all the control modules they will be adversely effecting the running of the car.
I would get all the control modules read out and fault codes reset and see how you get on.
Low and dead batteries can bring on the strangest of fault codes. Some you would think would have nothing to do with a battery!
Ive read thought your post a few more times, a bit tricky at first to fully understand due to the lack of full stops and comma's. However imo it does sound as if your battery is completely knackered and won't hold a charge. Get a new battery and get the cars control module fault codes reset.