I could not stand it anymore! With the help of this forum again and again I got the great Walmart H8 battery for about $180! Way, way cheaper than anywhere else. 900 CCA too.
Note they have two H8 batteries so be sure and get the Platinum version which has an additional year of warranty and is an AGM battery .

Platinum H8 battery

One strange negative is my stop/start which has been dead for over two years is now working perfectly! Which I guess shows that the factory battery was declining and the car shut off the S/S system because of the battery condition? I have never got a low battery message and everything else in the car works fine.

The after market trunk closing module seemed to have a few hiccup's with the battery change? It would open fine but only click when trying to close the trunk. But after several cycles of playing with the remote and the trunk buttons it seems to have cleared itself and is working properly again.

I still can't believe the battery lasted so long and it's a record for me. Since this after market battery only has a 4 year warranty I wonder how long it will last?
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Surprising number of low reviews for the battery, including for warranty issues.

 

I was rather surprised too at the nine year life of my X250s original Varta. We can't get Varta here but the Interstate Battery premium version for the XF just happened to be absolutely identical except for the stickers. Fingers crossed that it goes nine because it was nearly $300.

 

Get yourself a battery tender/maintainer and use it regularly and your new battery should last 10 years plus, CTEK is a popular brand around here.
I have been using a tender (not a CTEK) on the F-Type since I got it just over seven years ago now, more frequently in the last two or three years, and the original battery which is at least nine years old (car built Oct 2014, battery sure to be older still) is still going strong and has never given me a single problem.

 

Yes good advice as always! I never used a tender for the factory battery so right now I don't have a built in tender just my old stand by external Sears battery changer and my stout DC 50A power supply for use with SDD.

So we will see how it goes.
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Just make sure you always lock your car after parking it.

 

If it makes anyone here feel better, our 2020 Mercedes GLC300 will give a low battery warning if you leave the car door unlocked for half a day. So this silliness is not just Jaguar.

 

I have never reset my BMS system and I do have a working SDD. But after I reset the service indicator using my little cheap Autel AP200. Which I found on sale some time ago for around $25 but even at $50 it is a pretty good value for any XJ owner.
It's only $40 here;



Been using it to reset the oil service light but found out today it will also reset the BMS for both batteries!
So what the heck I reset both batteries.
Not sure how to tell what it did as I don't have any dash board messages.
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This discussion hit home with me!!

Just yesterday, I had both the front doors of our 2016 XJ open, as I was cleaning the windows. After just 3-4 minutes, the "low battery" warning came on. First time this is happened. The car doesn't go on very many long trips, usually just 15-30 minute hops around town. Sometimes even shorter, and I know that this isn't good for the battery (or for the engine's oil life, too). So, today, I put the battery charger on the car for a couple of hours.

However, I don't like to take chances, and a little over 3 years ago, when the car was in for it's annual service, and the car was 4 years old at the time, I had them install a new battery. They put in an Interstate MTX-49/H8. It carries a 3 year guarantee, and I'm now out of the warranty period, so anything that happens, is on me. I'm no stranger to working on my cars, as I've been at it for around 50 years, and a battery swap, at least in the past, was never a big deal.

Could someone correct me, if I'm wrong, but I thought that I heard that when you change a battery in one of these later model Jags, there's some sort of "reset" you have to do, in order for the car to "recognize" the new battery. Is this true? And are there any other "tricks" that I should be aware of, were I to do the swap myself? With respect to the battery itself, I was doing some "internet shopping", and along with the previously mentioned Interstate, I've also seen the Die Hard AGM, in the H8 group, as well as the Odyssey Group 49. Anybody have any experience with either of these two batteries?

TIA!

 

Walmart has the best prices for AGM batteries but when a certain battery group goes out of stock, it's out of stock nationwide for months. So if your battery failed within the warranty period your out of luck. It happened to me on my Walmart AGM H7 for my XF. For weeks, they assured me, a new shipment will be arriving and nothing happened, Finally I got fed up and told them, I want my money back. They gave me a hard time and if I get a refund, it will be a partial refund. Eventually after talking to the branch manager and showed him the scanned receipt that the battery failed, he then gave me a "full refund".
I bought an Interstate H7 AGM Battery at NTB (a little pricey than Walmart's AGM H7) and never looked back.

 

I went with the Walmart branded battery. It came with a 4 year warranty, and I could bump it up to 5 by using my Amex for purchase.

I did not need to do a reset of anything other than windows. My experience is here with the replacement effort. Truly no big deal.

 

It's a bit of a mess!
Jaguar says you need to reset the BMS (Battery Monitor System) when replacing the battery. BUT in that same document it says this is NOT required because the BMS will perform a calibration routine over time.
Note the wording in the service manual;





I have attached several pages about the BMS from the manual. We have had Brutal a factory Jaguar mechanic state that he does reset the BMS but thousands of cars are never returned to the dealer for battery replacement so resetting the BMS is rarely if ever done on most Jaguars.
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