Originally Posted by jagtoes

The battery monitoring system module is integral with the battery negative cable and is controlled by the ECM.
If a new battery is fitted to the vehicle, the battery monitoring system module will require re-calibrating using the Jaguar approved diagnostic system.
BATTERY MONITORING SYSTEM
Periodically the battery monitoring system module will instigate a self-calibration routine. To self calibrate, the battery monitoring system first charges the battery to its full condition.
• NOTE: If the vehicle is only driven for short periods the charging process could take a number of days to complete.
Once the battery is fully charged, the battery monitoring system will discharge the battery to approximately 75% of its full state of charge, but never lower than 12.2 V. The time taken to complete this part of the routine is dependent on the electrical load on the vehicle.
When the second part of the routine has been successfully completed, the battery monitoring system will return the battery to its optimum level of charge. The optimum level of charge will be between 12.6 V and 15 V, depending on battery condition, temperature and loading.
The battery monitoring system module also monitors the battery condition with the engine switched off. If a low voltage condition is detected the module can request the infotainment system is switched off to protect battery voltage. Once the infotainment system has been switched off, the vehicle must be run for at least 5 minutes to charge the battery before the infotainment system can be operated with the engine switched off.
The battery monitoring system module measures battery current and voltage, which it communicates to the RJB over a LIN bus connection. The RJB transmits the battery information to the instrument cluster over the medium speed CAN (controller area network)bus. The instrument cluster acts as a gateway between the medium and high speed CAN bus networks, and transmits the battery condition information to the ECM over the high speed CAN bus. Based on the information received from the battery monitoring system module, the ECM will control the output from the generator and request the switching off of electrical loads if necessary.
CAUTION: Due to the self-calibration routine, it is recommended that all power supply diagnostic testing is carried out using the Jaguar approved diagnostic system rather than a digital multimeter
The battery monitoring system module is able to generate DTC's to help diagnose battery or generator power supply issues. These DTC's can be read using the Jaguar approved diagnostic system. The Jaguar approved diagnostic system can also be used to implement a battery and generator self test routine. For additional information, refer to the Diagnosis and Testing section of the workshop manual.
If a fault is detected, the ECM will override the battery monitoring system module. The battery monitoring system module DTC's can be used to help diagnose battery or generator power supply faults. The
DTC's are stored in both the RJB and the ECM. The Jaguar approved diagnostic system has a process for an automated power supply diagnostic procedure. The procedure provides a menu driven process to locate a fault in a logical sequence.
The procedure uses the capability of the battery monitoring system and generator LIN bus controlled functions to provide current flow information and will detect if the battery monitoring system or generator are functioning correctly.

Originally Posted by bocatrip

According to what I can understand from your post...since I just replaced my old battery with a new one, and used a battery pack to keep the electrical system alive during the replacemnt.....none of the diagnostic equipment Jaguar has equipped my 2010 car will be doing anything useful. I bypassed everything with my battery pack and had bascially not reset anything other than the one touch down postion for the power windows. Should I be concerned?

Originally Posted by jagtoes

I don't see any information as to what the down side is by not having the system reset. That doesn't mean that there will be a problem but I would believe there is some technical reason to reset the system. Over charging or under charging ????????? I would ASSUME your monitoring system would still recognize the old battery and charge accordingly. Is that good or bad I don't know.

Originally Posted by bocatrip

Update Part 2: I replaced my 2011 Jaguar battery today with a Walmart Everstart Maxx H8 manufactured January 2018. I was under the assumption that my older battery had a reading of 12.5 after a load test. Now.... after replacing the older battery with the Everstart and checking my 2011 Jaguar Battery sitting in my garage with my voltmeter it is readying 12.78!!! Where did I go wrong? I guess the battery was not the problem causing my Centek 3300 from going to amber to green somewhat regularly but another underlying issue? Currently I have the new battery that has been installed charging with the CTEK 3300 once I got home from the install. It is too difficult to check voltage at the battery but I can only observe how long it takes for the charger to go to green from amber and what happens after that. To be continued.

Originally Posted by jagtoes

That's correct as a 12 volt battery has 6 cells at 2.1 volts each so a resting voltage would be 12.6 volts. As for checking the voltage at the ctek or when the ctek is off here is the way I do it.

Originally Posted by bocatrip

Thanks Jagtoes, but I'm not sure what I should be looking for in your pic of the rear or how or what you are using to check the voltage.

Originally Posted by jagtoes

I don't see any information as to what the down side is by not having the system reset. That doesn't mean that there will be a problem but I would believe there is some technical reason to reset the system. Over charging or under charging ????????? I would ASSUME your monitoring system would still recognize the old battery and charge accordingly. Is that good or bad I don't know.

Originally Posted by bocatrip

Jagtoes, Of course after your detailed description of the battery monitoring system, it gets me thinking of any future issues. In the almost 4 years of ownership of my 2010, I have not had any electrical issues. The entire time I have been using the CTEK 3300. Yes, the battery I replaced is actually still quite good reading 12.79 volts out of the car. So, that was a waste of money purchasing a new battery, but it's in the car and of course staying there. Now I have two concerns. 1) Why was the CTEK going back and forth from amber to green over the course of many months? I'm noticed it doing it a number of times a day and yet my battery is quite healthy. I did call CTEK and they told me to check my battery which I did. I'll keep an eye on it but have a feeling it will be doing the same with the new battery. I did try another CTEK with the battery and it did the same thing eliminating the possibility of the CTEK being faulty. 2) Will the CTEK do it's thing correctly with the replaced battery that I had my Indie replace even though I have not reset the battery monitoring system? I've read a post of a member that replaced his 2010 or later XK battery without any issues. So far the new battery presently in the car, turned the CTEK green this morning. I'm not familiar with all the cycles the CTEK goes through and my model the 3300 doesn't show all the steps of recycling. I'm also planning on upgrading the CTEK to the model showing all the steps of charging anyway. Should I be concerned? What does Jaguar actually do (if anything) when it comes to resetting the battery monitoring system?

Originally Posted by jagtoes

I have the Ctek MUS 4.3 charger. It has a 7 step charging method and also an alternator tester. The 3300 was an earlier system and was also sold by a lot of car mfg under their logo. Jag , Ferrari , Porsche , AM and other. I assume if you look at the Ctek info on the 3300 it probably cycles between the amber and green during it's initial charge sequence. My thoughts are that when the battery loses some of the charge the Ctek goes back to amber until it reaches the green charge state. If you can try taking a reading from the battery (trunk post) while the green light is on and see what it reads. Do the same with the amber light and see what you get. As long as you are over 12.6 V you should be OK.

Originally Posted by bocatrip

However, since I don't have your set up I need to open the trunk and the light comes on off setting any reading I might get. I don't feel like pulling fuses in order to eliminate the trunk light drain.

Originally Posted by kj07xk

Just leave your trunk open, the lights turn off after awhile.

Originally Posted by pwpacp

That is a great question. On the 5.0 XK is there a DIY process to reset battery memory after exchange or is this something only a dealer can do?

Originally Posted by jagtoes

As I understand it you must use a JLR type diagnostics system. There might be other OBDII tools but I have not heard of them. Also I think the down side of not doing the reset is that the charging rate would function differently which could effect the life of the battery .

Originally Posted by bocatrip

Just had a lengthy conversation with the shop foreman at my local dealership whom I have gotten to know fairly well. We spoke about battery replacement on the 2010XK+ with the need to reset the battery monitoring system. He says that for the most part he doesn't reset any of them, especially when he gets busy. He has never experienced any issues and told me the monitoring system is going to over a period of time learn what the battery's condition is and how to charge it. He said if a customer asks to reset the system, he will be happy to charge them the $175 for something he considers not neccessary. I've heard from previous posts there are dealerships that don't bother and others that will reset. Right now, my car is performing as it should without any reset. I was wondering if the CTEK is able to charge properly, but considering it's a smart charger I'm fairly confident it too would work around and learn how to properly charge.

Originally Posted by jagtoes

Interesting questions and answers. It is interesting trying to understand the logic of the manufacture who designs in a requirement but yet the dealer intentionally doesn't do it nor believe it does anything. Kind of confusing. I wonder if there is an explanation some place that tells us why and what the reset actually does. Thanks for the feedback.