I would trust Rock88 as he seems to have mad mechanical skills.

 

I got it replaced yesterday. Costco has the Interstate for $177. I thankfully had a co-worker loan me a cool contraption that jump starts or powers your car if the battery is dead. My battery was dead and I could not pop or open the back without power booster. I plan on now picking up one for myself. That thing was amazing.

 

Well I'll be...........

 

Thanks for the tip on the auto up/down reprogramming. My auto down was working but not the auto up function. I will re-program when the car gets back this week. Everything else was still programmed with the exception of the clock and time.

 

Another option for those worried about losing settings, etc...You can leave a Battery Maintainer connected to the car while you replace your battery. It will keep enough current in the system so all of the modules retain their memory. Then after battery is installed, disconnect the Maintainer/Trickle Charger and it is like yo never touched it! I had to do this on many of my prior Porsches that had the encrypted stereo ant-theft codes. If battery power was lost, you had to go through a whole procedure of entering an unlock code....and if you lost the little card with the number...Well then, you go tot send it back to Germany to get it unlocked/re-programmed (or buy a better stereo and upgrade - haha).

DC

 

Well, here is a technical question for you. Say you are replacing the AGM battery with an Antigravity lithium. Do you use a standard AGM maintainer or a lithium maintainer in order to retain memory?

 

Does not matter. All you are doing is keeping the modules charged to maintain memory, while you switch the batteries. Once you have whatever battery you choose installed permanently, use the appropriate chargers/maintainers for your new battery.

DC

 

I'm not convinced you can use a CTEK for that trick - unless there's a battery connected my CTEK won't output any volts.

 

Let me clarify. YOU HAVE TO USE A DEVICE THAT WILL MAINTAIN VOLTAGE while you disconnect and re-connect/install the battery. Trickle Charger, Battery Charger, Battery Jumper, Another Battery. Something that produces ~ 12 volts, connected to the car via Terminals, Charge Points, Unswitched Cigarette Lighter/Power Socket, etc..

DC

 

Yeah, that was my point, too.

 

I'm not sure that you need an AGM if the Start/Stop has been disabled (that's the only reason to use AGM over LA).




Most OBD II readers for JLR allow the user to reset the BMS - It is not essential from my understanding, but for belt and braces it's been implemented in the external devices, so to me at least, may have some value....and we all know how tetchy these cars can be with the electrical side of things.


At the end of the day you can simply remove and drop in another 12v source be it whatever technology, and it will work to a greater or lesser degree.
Or, you could buy an equivalent or the same AGM, reset the BMS as it (should), would be done in a dealership..the difference, who knows?

 

Isn't the charging circuitry designed for AGM which has slightly higher voltages which may have an adverse effect on non-AGM batteries?

 

The older dual-battery Fs have AGM batteries from the factory.

In theory, there could be a difference to the BMS...but in practice?


"Albert Einstein has a famous quote: “In theory, theory and practice are the same. In practice, they are not.”
Or was that quote from Yogi Berra?

 

Dare I call it a "smart alternator' and "Intelligent charging" system?...it will adapt, i.e increase/decrease V and A depending on what the BMS observes on the -ve terminal, so in theory, no.


The snippets I took from the TopIX are for my car 2015, one battery with DC/DC convertor, so won't apply to dual battery cars from earlier Manufacturing Years. It clearly states that standard LA batteries can be used in cars without the Start/Stop feature, so I assume that this setup is designed and used across a range of JLR products that don't have start/stop also.

 

Impressed with all your posts - great technical knowledge...

Thank you.!!

 

Don't laugh, but I just replaced 2 batteries on my Jeep Grand Cherokee.
It still has a smaller battery for the stop/start, etc (not sure about the etc).
The smaller battery actually cost nearly as much as the main starter!!

Anyway, the point of this reply is the following.
To avoid losing all settings, I connected a small battery to the jump charge terminals in the engine bay.
I used a lead/acid battery but some say a simple 9 volt disposable will do the job.

Can't see why a Jag would be any different.
Just connect power to the charging terminal in the engine bay and go for it!

 

I believe the only settings I’ve lost in the car from a battery swap or disconnect is the window auto-up feature, which is easily reset. Memory seats, audio settings etc were fine.