Rochelle battery is starting to die. Need to replace it. Wondering if it's as simple as replacing the current battery with another compatible GMT battery? Is there any computer work that needs to be done by the dealer? Should I leave it on a trickle charger as I'm replacing it? Anything unusual that needs to be done or can I just swap it out like any other car?

 

Rather than opening a new thread, please do a search on "Battery" as this subject is well documented. Also, if you would be so kind as to follow the new member procedure.

 

I really don't want to post new but I read through every 351 post that had "battery" in its topic and none of them specifically talked about how to REPLACE the battery. Many talk about what happens why a battery drains, or died and the trunk won't open, etc.... but none specifically talk about the battery replacement procedure. Perhaps you could be so kind and point me at one of the pertinent posts that you think addresses this specifically. Perhaps it's a good topic to make a sticky? Thank you

 

The battery module needs to be reset at dealer. After replacing battery.
Reset windows, clock and parking brake. You can use another brand battery as long as correct spec for cca. Interstate is a great brand and many other batteries over the years i have tested dont actually test up to the specs on the battery

 

Thanks Brutal. So is there no need to run a trickle charger to maintain current while swapping out the battery? Sounds like I have to spend the money at the dealership to reset things no matter what? Like to do it myself if possible but I understand some things are "dealer only"

 

that is proper procedure for correct charging as is never hooking up a charger or cable to the negative terminal on the battery, negative always goes to a body ground in trunk. The battery module does not see the current in or out then, not to mention many times people catch the module power wire and short to ground blowing out the fusible link to it and then car does not charge at all. That said there are many batteries replaced that never get reset because hey it's a battery how hard can it be.

 

Also never connect any kind of charger while the battery is not connected. The charger requires the load of the battery to properly regulate the output voltage. Some chargers could output a high enough voltage to damage electronics, without the battery load.

 

I'll be visiting Interstate Battery near me to have them test the battery & replace it if the confirm the occasional "low battery" and a new one is needed.
They're familiar with the drill on vehicles that are sensitive to the battery being disconnected.
As long as the salesman is experienced & familiar, they put a 12VDC source in line while they're replacing the battery, and the car never knows that the battery was replaced.
The only reason the vehicle needs to have the "new battery" reset is because it lost power.

Another alternative is subscribing to or buying SDD to reset it yourself.

 

not true, the battery module that is clamped on the negative terminal of the battery is in direct comms with the ecu and the ecu controls charging and messages. You reset not because the car lost power but because it has monitored voltages and amps going into and out of battery for its life.. So it pretty much knows correct battery condition and proper charging. When you replace with a new battery you tell the ecu this has been done and it clears stored info and starts fresh. You dont lose anything but window 1 touch, park brake setting, clock. Radio presets etc all stay in place

 

Well then, I stand corrected. I don't recall where I'd gotten the bad guff from, but sorry to pass it on.
What happens if the battery shop does use a battery surrogate while they replace the battery?
Regardless, that's the sort of thing I have the SDD for.

Thanks Brutal.

 

Brutal there is mention in the shop manual that the BMS self calibrates every so often.
So that will allow the BMS to correct for a new battery and be up to date?
Or not?
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That is an interesting question @Brutal Any thoughts?

 

Curious - what is the purpose of resetting the battery module? What does that "do" or what is it's purpose? I've recently put in a fresh battery on my XJ as well.

 

What I have been able to find out is with all the problems Jaguar had with the XJ and batteries that in 2013 or 2014 they upgraded the BMS.
What this does is measure the amps coming out of and going back into the battery. Then it models the condition of the battery and will set dash board messages about what it (the BMS) thinks is going on with the battery.

So if you install a new battery you have now lost all the prior history because that battery is gone and has been replaced. Now in theory the BMS will be incorrect. The dealer can use the SDD tool to tell the car it has a new battery and to start the BMS over. I have also read that Jaguar realized not every owner would know to reset the BMS when changing the battery out. In the shop manual there is mention that the BMS will self calibrate (what ever that means!) every so often even if it's not been reset. This is to try and keep the BMS correct and up to date on the batteries condition.

This is also why you should NOT hook the negative battery terminal to your jumper cables. Attach the negative lead to the base metal of the car. This way all the current will go thru the BMS and be counted.
Note the blue and white wires attached to the negative battery post in the picture below. This is the BMS (Battery Monitoring System)



Also note the nice corrosion I have on my small battery negative post. Oh well something else to clean up!
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Very helpful explanation Clubairth - Appreciate the response and picture.

 

Scheduled an appointment after changing out my original battery for an interstate. Expensive but worth it in the long run. Made an appointment with local dealer to have them update the voltage regulation through the software. Got there and the service advisor let me know that there's no need for the software update.. at least on my 2014. I didn't ask about earlier years. The automatic up and down windows, the clock, and the parking brake can't all be reset easily yourself. So don't waste the time and money and having a dealer change out your battery. There is no need. Also no need to maintain voltage when you swap it out.

 

That’s funny they said that. There is a battery management system (BMS) reset option on my Jaguar specific OBD scanner. I think that is what others were suggesting be done. Agreed that the windows, EPB, trunk, and sunroof can all be reset easily yourself.

 

Clubairth1. The wires are not the bms. They go into the bms which is the black box on the negative terminal they go into. Also while the bms self calibrates this is not a reset of monitor info and when replacing a new battery be it the main or the aux you have to reset adaptations just like trans and ecu have adaptations. If jaguar did not still or require this to be done they would not pay us for sdd use to reset this info when replacing a battery under warranty. They would not pay and state "not required."

 

The question is not whether Jaguar recommends re-setting the BMS, it is whether it is absolutely necessary. I suspect you can get away with not doing so. The system has to have the capacity to adapt to changes in battery condition.

 

Does anyone know if there's a way to reset the rear side window blinds? One of mine stops about an inch short.