Driver side Main Battery

Passenger side Starter battery
I know this has been covered in many threads before, but i want to clarify since i believe most of those conversations have been for 1st gen GTC/CFS and things may be slightly different on my 14 FS
I currently do not have any battery issues but want to understand for the inevitable future....

My Main battery is the larger AGM one in the pics and is on the left side. I gather the smaller one (on the right side of the car) is the starter and has a pyrotechnic isolator attached.

My question to you all - in the event that either one of my batteries fails or goes dead and i need to replace it, is the sequence to disconnect them (avoiding the pyroblast ) as follows :

1. Starter battery - negative first, positive second
2. Main battery - negative first, positive second
3. Exact Reverse procedure to connect them back?

Also - using a battery tender that isn't Ctek - I have regular clamps on my tender, so it seems i need to connect the positive to the positive, and negative to a metal part on the car (Someone please clarify if my car is positive or negative grounded from the pics above) - any suggestions where i can hook that negative up to the battery compartments in the car for ground?

 

Thanks for the info
Ok seems doable (except for removing the damn fuse box just to get the main battery out)

I can buy the Ctek with a 12v adapter thingy and plug it into the 12v socket in the boot and charge both my batteries together but it means i have to buy a ctek 7000. Since i already have a large amperage battery charger/tender i was looking to save some money by hooking it directly up to each battery in winter (less use) and topping it up. wondering if anyone knows where i should clamp the negative (ground) in the compartment are assuming the car is negative ground.

 

Thanks for additional info. That video is pretty clear (though I don't have that humongous attachment on the Main battery. I think Bentley changed things for the newer models.

Ya actually my battery charger has auto detect for various battery types (AGM, etc) so it shouldn't be a problem other than just alternating the charge between the batteries.

 

The pics of the batteries for my 2014 is right at the top of this thread. I attached both sides for reference

 

Yup. Lightbulb just went off in my head. I just uploaded some FS booty

 

Ya slightly unloved by most due to polarizing design language but i love it! I am trying to find a good source for aftermarket bits and bobs but very few available for 2014 Gen 2 (e.g. carbon fiber interior MMI dash panel instead of piano black etc.) Also can't find much on YT in terms of hacks and mods done on this thing. All the resources are for the Gen1 or GTC
Got any good links to products or videos for mine?

 

On Continental GTC models if there is a separate positive cable to the starter battery that is live until you disconnect the left side battery does that mean that the starter battery will also charge when charging the main left side battery?

 

Sorry, this is incorrect. As a point of clarity and for posterity's sake, there are two mistakes in the above.

The starter battery is located on the RIGHT side (not the left), the Main battery is located on the LEFT side (not the right). It is an industry standard to locate LEFTSIDE/RIGHTSIDE from the prospective of sitting in the car seat and looking out the windshield. This eliminates the possibility of double definitions as if you were standing at the grille of the car staring at it backwards which happens sometimes.

Second, the main battery on the LEFT is an "Absorbed Glass Mat" battery, it is also known by its acronym AGM (not AMG). AGM batteries differ from lead acid batteries as they are essentially "dry" and not filled with liquid acid. AGM batteries charge differently than lead acid batteries. They require a lower voltage deeper cell charge. Good battery maintainers offer a special charge and maintenance cycle for AGM batteries that differ from lead acid batteries like the battery on the RIGHT side. Lead acid batteries take a higher voltage and a faster charge, so a maintainer used for the rightside starter lead acid battery should be maintained on a lead acid cycle, not an AGM cycle.

One final point for clarity's sake, the + terminal found in the engine bay is a direct connect to the LEFTside MAIN battery. It should be used only when the MAIN battery has gone completely flat and has locked you out of the car. By providing a 12v "supply" to this terminal, you will then be able to unlock the electric trunk giving access to the two batteries. This front engine +v terminal should NOT be used to try to jump start the car as there is no connection to the RIGHT side starter battery. If both batteries are flat and you need to jump start the car, there is a procedure for that, but essentially you are jump starting the starter battery - AFTER the main has been recharged. If both batteries are flat, jumpstarting the car from the starter battery will not start the car and keep it running with a dead main battery too.

Hope this helps!

 

Greetings Rico:

Just correcting this incorrect statement as some who will use the search feature in the future might land here and get confused by it:

No the left starter battery will not charge when charging the main right AMG battery ...

It was not intended to be a personal attack which I do not engage in on forums in which I participate. Just setting the record straight.

All the Best....

 

Hi Rico,

No problem. Let me explain about "the record". Someday, when we are both gone, future members will be using the search feature when they have problems such as battery issues which are common on Bentleys (and most cars today using modern electronics). If they are skimming through posts on numerous threads (as one often does with so many posts on a single topic) and land on post #14 in this thread, and if they read this line:

No the left starter battery will not charge when charging the main right AMG battery ...

they can mistakenly conclude the battery on the leftside is the starter battery and the battery on the right side is the main. This is incorrect. It is also incorrect to call the main battery an AMG battery; it is an AGM battery. At best, it causes confusion, at least it causes conflict with other correct information that is also part of the record on this forum.

For the newcomer to these cars, everything is a discovery, even the simple things that you and I can take for granted. It is common to suggest to a new member to use the search feature. It is a great feature of car forums if the record is correct. My reply was strictly technical and based on issues. There was no condemnation or personal attack of you as the author, just an address of the technical mistakes in the statement.

Hope this helps......