[Proxy]

I have Bluetooth battery monitors on my two 12v batteries. For months the charging voltage for the Main Battery is about 14.4v and the voltage after sitting for many days without any charging is just above 13.0v. Over the past month the charging voltage has dropped to 13.6v and the voltage after shutting the car off drops to 12.4v. The Aux Battery has been consistent over the same time frame and shows no signs of degradation. The build date was more than 4 years ago.

So, what to do? (Still under warranty)
A. Replace it myself
B. Wait for it to die (have jump battery in car)
C. Remove the battery monitors and take it to the dealer. Hope they test it, it fails and they replace it.

What happens if I choose scenario C and it passes the test? Do I then have to pay for the diagnosis?

 

[Trielectric]

What would you do if it was an ICE car that had the same voltmeter readings off the battery?

 

[Proxy]

@Trielectric I would not know about it since I wouldn’t monitor as it is not as big of deal in an ICE vehicle. I or anyone else could insert the key in the door (just like the Jag), pull the hood release and jump start the car (unlike the Jag). The I-pace would require specific knowledge and skills and would probably end up on a flat bed after loosing a few hours of valuable time. I’m not the only one driving the car.

Also, the 12v battery wouldn’t be under warranty. Plus, the ICE car could probably drive to a place to replace the battery.

 

[Ayepace]

Option A gives you peace of mind.

Option B gives you maximum use for the cost of the batteries but risks an in-traffic incident.

Option C does not require removing the monitors (at least not at the dealer I've been to) but will cost you at least 2 hours of labor charge if they test good. That is more than the cost of replacing 1 battery. The cost will be covered by warranty if one tests bad.

Your posting suggests that you can't do battery replacement yourself. Any shop or shade tree mechanic can do the job. The large battery is readily available from auto battery sources. The small battery is available from JLR parts departments and one mail order place in MI, or you can use a readily available alternative following my instructions. 2020 MY and before Auxiliary battery replacement

 

[Rufus]

I just replaced both 12V batteries last week at the local JLR dealer. They were about to hit the four year mark and started acting up.

It went like this: after a couple of weeks sitting in the garage, in mid-February the car gave a few errors ("brake pedal feel reduced", "charging error", etc.), but moved out of the spot. Then it refused to move, just sat there with lights on. I grabbed another car for the family lunch outing, and when I returned a couple of hours later the Jaguar had forgotten about the fit, and was moving normally. Drove it about for a bit right then, and again in the following days. All normal.

Then after another couple of idle days (and re-reading here all about it, talking with the seller about battery replacement options, etc.), it happened again - get out of the spot, swoon, wake up again half-an-hour later. This time I just called and drove it to the dealer, swallowed the 500€ battery replacement cost, and ended up paying a total of 680€ with the four year service done early.

I'm hoping the car is good for another three or four years of uneventful driving. This is just my little bit, with thanks for all the good info Ayepace and others have contributed here.

P.S. it's not just Jaguars with poor warnings about 12V batteries. A Leaf died on me after a few errors with starting because of the required brake pedal stomping - seven year old 12V battery easily replaced. A Fiat 500e died silently overnight and had to be towed because the (not yet two year old) 12V battery mysteriously wasn't charged. The manufacturers should really get on this, it's inexcusable that they have the CANBUS data and the apps don't give a peep.

 

[Proxy]

@Ayepace Thank you for the information. Two hours of labor to check the battery and having to go to dealer and possibly pay for the labor… no thanks. I will go with option A next week unless B happens first.

Follow up question: when I changed the 12v battery on a Mini I also programmed the car for the new battery so it would charge it properly. Does the I-pace need this done?

 

[Ayepace]

The larger startup battery has a Battery System Module (BSM) on the negative post. Per the manual it should be reset. However, JLR has used these for many years on ICE models. People have reported that it resets itself after a short period of usage. Others here an on the UK forum have replaced the startup battery without resetting the module and haven't had any issues. There are code readers with the ability to reset this that most shops should have if they worked on JLR products over the last 10+ years.

For startup battery replacement

• Unclip the positive post cover from the connection to the battery
• Disconnect the DC/DC converter ground strap from the BSM and move the DC/DC converter ground cable+positive cover out of the way
• Disconnect the body ground strap from the BSM
• Disconnect the small electrical connector from the BSM
• Remove the BSM from the battery negative post
• Disconnect the positive cable connection and insulate it
• Remove the battery hold down
• Remove the battery
• Installation is the reverse of the above.

Official instructions start with removing the storage box but others have done the job without doing that step.

 

[Rocco]

Hello everyone.

I’ve got a little problem…
I replaced the 12v startup battery and the buttons on the steering wheel stop working. they are not illuminated at all.

I'm assuming it's a fuse issue, but I don't know which one is it
Everything else works great, drives and shows no errors.

 

[Ayepace]

Others have reported this happening to them but it they resumed normal function and lighting after a few drives.

 

[densjag]

I have Bluetooth battery monitors on my two 12v batteries. For months the charging voltage for the Main Battery is about 14.4v and the voltage after sitting for many days without any charging is just above 13.0v. Over the past month the charging voltage has dropped to 13.6v and the voltage after shutting the car off drops to 12.4v. The Aux Battery has been consistent over the same time frame and shows no signs of degradation. The build date was more than 4 years ago.

So, what to do? (Still under warranty)
A. Replace it myself
B. Wait for it to die (have jump battery in car)
C. Remove the battery monitors and take it to the dealer. Hope they test it, it fails and they replace it.

What happens if I choose scenario C and it passes the test? Do I then have to pay for the diagnosis?

I previously wrote that I was concerned about the possibility of my batteries failing since my 2020 just turned 3 years old. Only warning I ever received was notice of low coolant fluid. Brought
the Jag to dealer asking they check the coolant as well as the batteries. Turned out that main battery failed whatever test they do and was replaced under warranty at no charge. Other battery
checked okay and they told me to bring the car back in another 6 months, assuming it does not fail in the meantime, to be rechecked. They completed all necessary updates and returned the car
to me next day. Very happy with service I received at Palm Beach Jaguar, Florida.

 

[Proxy]

Well, I flinched first. I removed the battery and had it tested at a car parts store. It tested good so I didn’t want to waste my time and pay Jag to get the same result. The post on the original battery was stamped 46 over 18. I assume this means manufactured the 46th week of 2018. New battery installed. Thank you for the advice and instructions. I did not remove the storage box but opened the windshield washer cap and pulled up the right side plastic a little bit. There is a tab that goes under the painted front body panel. So I had to flex it back a little bit and press down on the inside front corner while moving the panel toward the grill to reinstall it. Only other thing I would add to the instructions is to remove the vent at the battery before removing the battery hold down.