Since it's going into winter here in the Pacific Northwest I decided to purchase a Ctek trickle charger. I ended up installing it directly to the battery terminals in the trunk for the photo attached. Will this be sufficient since I'm by passing all of the battery maintenance electronics in the car?

 

Looks like you have a coupe…instructions will tell you to install power to the distribution bar (it whatever is called) and negative to a chassis bolt. On the convertible, it’s a bit different battery location, power goes on the battery and ground to chassis bolt, so it doesn’t bypass the BMS. Have done both successfully.

 

This is what I ended up doing in case it might be of any interest to you. I wanted an approach that would make it super easy and encourage me to consistently plug the battery to my CTEK every time. No opening hoods, not opening trunks and potentially interfering with rubber seals over time, etc…I don’t need premature failing batteries and all these random mystery low voltage related problems that would inevitably come if not plugging in etc…

It has been perfect. As you will see in the photos you would never know it is there and there have never been any issues. I dump a bit of dielectric grease in the plug once a driving season as a precaution, but I can tell from inspecting it every once and awhile that it is overkill. The plug cover has a perfect seal as far I can see. I spray directly around there with my pressure washer during regular cleanings. No problem.

Doesn’t bypass anything either. Charging at the front is the recommended way of doing it as I understand it. That is what the dealers do on their showroom floors usually.

https://www.jaguarforums.com/forum/f...-setup-280537/

 

@DMeister
Thanks for the link, this is exactly what I wanted to do but couldn't figure out how to get the box opened to access the positive lead from the jumper bar. Would you be able to give a bit more instruction on how to dismantle that box after I pull off the first two bolts to remove it from the chassis?

 

Hey there,

It’s coming up on 2 years since I did that, so I can’t quite remember the exact details other than what I said there where it was a small amount of screws and clips. I remember it being pretty self evident once taking a look there under that top cover. I assume your car, despite being older, would have identical parts there? I would imagine anyway.

There’s not much that can really be messed up there, so a bit of bravery goes a long way here. Honestly, it’s not a big deal. Sorry for not capturing a little more of the details there at the time when I put that together.

The end result is worth it in my view, depending on what your goals are.

 

I found that connector is long enough to connect to the "approved" points on the trunk/boot floor and still have the socket next to the battery as you have it. Though I leave the sucket under the battery cover and lift it and the cubby cover out when I want to plug it in - I turn the battery cover upside-down across the cubby "hole"and put the charger on that so it's not sitting on carpet.

 

If I understand you right, you don't need to unbolt the box from the chassis - the lid of the box unclips (about 3, if I recall correctly) from the side furthest away from the battery and then flips up to give you access to the mounting point you want. Negative goes to a floor mounted earth stud.

 

What are the approved points contact? I will have+ to battery terminal and - to chassis bolt would this be correct?

 

I found this on youtube and looks pretty straightforward:

 

CTECK battery charger installation question - Jaguar Forums - Jaguar Enthusiasts Forum

See post #17

 

I mounted the Ctek on my coupe in the fall of 2020. My JLR tech advised using a direct connection to the battery. There was a spare hole on one side and so I put the ring connector on the bolt there. Have enough cord to run it up and above the floor panel for easy connection to the Ctek

 

I don't understand why JLR Tech's advise to connect battery maintainer/chargers directly across the battery terminals. This isolates the Battery Management System (BMS) and leads to erroneous alternator charge cycles due to Body Control Module not having a record of the true state of battery charge. The BMS drives the alternator charge and 'discharge' cycles when the car is running, in an attempt to keep the AGM battery in optimal condition. The F Type charging system is much more complex than a typical AC to DC 14V output.

See posts 8 and 9 within the following thread for details of the multiple ways to 'correctly' connect a battery maintainer/charger to the F Type --> CTEK connections

 

I will copy your message and send it to my tech.

 

It seems to me some of you go to a lot of trouble for something so simple. For years now I connect my 1.5 amp or 3 amp "BATTERY TENDER" to the post under the hood. The car sits from October to April and I have never had a problem with any battery drainage. It's quick, easy, and simple.

 

I installed mine to the bar in my vert. I believe I got the info to do it on the forum years ago.

 

all sorts of opinions and theories.

Here is the reply from my JLR tech, not some newbie, a well-trained and experienced professional:

Yeah he is wrong the BMS battery monitor system is on the negative post of the battery you can see it, it's the little black box with a 2 wire connector on it. If you have the negative of the battery maintainer or the charger grounded somewhere before the BMS then it will be able to see the charge state of the battery. Basically if the positive is on the battery good and the ground somewhere on the body good. Amperage is the same throughout the circuit, if you take an amperage reading on the positive it will be the same as the ground. This is 100% safe and correct the way you have it setup as long as the ground side of the maintainer is not on the negative side of the battery. AND to be completely honest the system is not very complex... they make a bigger deal of the charging system then it is. I have seen MANY people change their own battery and never reset the BMS and nothing happens. To me its one of those gimmicks to get people to go to the dealer the computer will eventually see and learn of the new battery. The output of the alternator is never going to go above safe AGM charging limits. I wanna say 14.8 volts. It is a factory hard limit. It might peak from time to time right after start up but the system was designed with AGM in mind, anything over 14.8 causes damage so they limit the system. In my opinion it's safe and fool proof, kind of like red line they will not allow you to over rev the engine this is not going to allow the alternator to overcharge. Also I attached a screen shot from the workshop manual for your car stating the same thing I have been saying just in official terms and from Jaguar. Just in case the guy on the forum wants to say something else its right from JLR.

 

Yeah, the confusion is that when people say "connect to the battery" the assumption is that both pos and neg leads go to the battery terminals, which will bypass the BMS. Obviously connecting just the pos to the battery and the neg to a body ground is pertty mucch the same as connecting it the "approved Jag way" to the boot/trunk floor busbar.

 

@Valerie Stabenow I'm confused by your JLR Tech's detailed response, which corroborates my guidance "The ONLY method you should NOT adopt is to connect directly across the battery terminals" = "This is 100% safe and correct the way you have it setup as long as the ground side of the maintainer is not on the negative side of the battery" = " ! CAUTION - Do not connect the battery support unit ground cable directly to the battery ground terminal". This is contrary to your original post #11, where you stated "I mounted the Ctek on my coupe in the fall of 2020. My JLR tech advised using a direct connection to the battery". ???