[Ayepace]

We've seen a number of the auxiliary batteries fail. These are the small AGM batteries found in pre model year 2021 cats.

One can get it replaced while under warranty with a JLR replacement rated at 14AH, or purchase one from a JLR dealership if out of warranty

One can search Ebay (or equivalent) for the Exide EK151 that is an exact replacement rated at 15AH, but they ship from the UK or Latvia (as of this typing).

Battery dimensions are 150mm L x 90mm W x 145mm H.

I think I have identified two other alternatives from Braille that would fit the space.
B129 12AH 147mm L x 86mm W x 130mm H
B14155 15AH 147mm L x 86mm W x 147mm H

There are slight discrepancies in the dimensions but I don't think that will matter. 2mm higher for the B14155 isn't much. Smaller dimensions will always fit in.
Yes, the height measurement is to the top of the posts.

These appear available from a number of auto part vendors that specialize in racing parts. Jegs, Summit Racing, Raceparts, etc. Sourcing from these places would take less time than shipping from Europe.

Thoughts? Anyone else found alternatives?

 

[rcomeau]

We've seen a number of the auxiliary batteries fail. These are the small AGM batteries found in pre model year 2021 cats.

One can get it replaced while under warranty with a JLR replacement rated at 14AH, or purchase one from a JLR dealership if out of warranty

One can search Ebay (or equivalent) for the Exide EK151 that is an exact replacement rated at 15AH, but they ship from the UK or Latvia (as of this typing).

Battery dimensions are 150mm L x 90mm W x 145mm H.

I think I have identified two other alternatives from Braille that would fit the space.
B129 12AH 147mm L x 86mm W x 130mm H
B14155 15AH 147mm L x 86mm W x 147mm H

There are slight discrepancies in the dimensions but I don't think that will matter. 2mm higher for the B14155 isn't much. Smaller dimensions will always fit in.
Yes, the height measurement is to the top of the posts.

These appear available from a number of auto part vendors that specialize in racing parts. Jegs, Summit Racing, Raceparts, etc. Sourcing from these places would take less time than shipping from Europe.

Thoughts? Anyone else found alternatives?

Thanks. I'll forward this to my dealer! I have been waiting 2 weeks for one of these and the delivery date slipped from last Thursday to Monday earlier this week to no delivery date!

 

[JaggaWatt]

@Ayepace is this auxiliary battery also known as the TCU battery? I have MyPace (not Wattcat) and I can see the TCU battery percentage in that app.

 

[Ayepace]

No it is not the TCU battery. That one is located in the TCU at the rear of the vehicle. It has a non-rechargeable cell and a rechargeable cell. It should show 90% in WattCat at full charge.

 

[JaggaWatt]

So can anyone recommend how to monitor the status of the AUX battery?

 

[dernotte]

For info, the TCU battery is described here : What is the Auxiliary Battery used for ? (the small one)

 

[[email protected]]

My 12v battery was replaced by the dealer a few days ago. Part number is jde32902

Genuine OEM Vehicle Battery Part# JDE32902 Fits 2012-2021 Jaguar: Up To 35% Off On Every Order And Guaranteed Fit When You Enter Your VIN | Jaguar Cary Parts

2012-2021 Jaguar OEM Part # JDE32902 - Vehicle Battery

parts.jaguarcary.com

 

[rcomeau]

Just so I understand this (how many batteries does it take to run a car?)…

we have the high voltage battery that power the motor. Is that the traction battery?

we have a 12v battery that powers the electronics and is shared by other JLR cars.

we have a second 12v battery (auxiliary battery)?

we have a third battery in the trunk somewhere (TCU battery) that might actually comprise of two batterie, one rechargeable and one not?

do I finally have that right, or am I conflating the 12v and aux 12v which are one battery?
Thanks for clearing it up!

 

[Ayepace]

You have it right.

Big traction battery on the bottom of the car (part number varies by VIN) that powers the whole car at full power on. It costs $38,000+ and requires a lot of work and specialized equipment to replace.

Up to MY20, they have two batteries in the frunk area. The larger 99R/T4 flooded starter battery (T4K4462) on the right side of car and the small auxiliary 14Ah AGM battery (JDE32902) on the left (the purpose of this thread). Its voltage is displayed in WattCat (or equivalent), using https://ipace.herokuapp.com/static/param.html, or some people have added Bluetooth capable battery monitoring devices available at Amazon and other places. The voltage reported may show charging voltages at time (15+ volts). This is a good thing. Below 12.2V is a bad thing.

Starting with MY21 the small auxiliary battery has been discontinued and they only have the starter battery.

The TCU battery (T2R23864) is stored internal to the TCU as shown in the picture in the thread from dernotte. It is a battery assembly with two batteries. It should last at least 10 years. The TCU is located behind the left loadspace trim panel.

(Part numbers subject to change.)

 

[mjpsammon]

Is there a TSB on this? Or does the battery have to fail to get it replaced under warranty?

 

[Ayepace]

Failure is your only option. No TSB.

 

[rcomeau]

You have it right.

Big traction battery on the bottom of the car (part number varies by VIN) that powers the whole car at full power on. It costs $38,000+ and requires a lot of work and specialized equipment to replace.

Up to MY20, they have two batteries in the frunk area. The larger 99R/T4 flooded starter battery (T4K6642) on the right side of car and the small auxiliary 14Ah AGM battery (JDE32902) on the left (the purpose of this thread). Its voltage is displayed in WattCat (or equivalent), using https://ipace.herokuapp.com/static/param.html, or some people have added Bluetooth capable battery monitoring devices available at Amazon and other places. The voltage reported may show charging voltages at time (15+ volts). This is a good thing. Below 12.2V is a bad thing.

Starting with MY21 the small auxiliary battery has been discontinued and they only have the starter battery.

The TCU battery (T2R23864) is stored internal to the TCU as shown in the picture in the thread from dernotte. It is a battery assembly with two batteries. It should last at least 10 years. The TCU is located behind the left loadspace trim panel.

(Part numbers subject to change.)

Thanks for the great summary!

I had texted the part#s to the service techs and they actually approached the JLR engineers (despite it all, I feel they are doing their best) but the engineers said the batteries had to be the exact models from Jaguar (not even Land Rover). I was there this morning swapping out the loaner and they can't even get a delivery date for the aux battery. I was there because I got a flat yesterday so I had to put the spare on the Versa (-10c, so fun) and now have a Mazda CX-3. My 4th rental since this started 3 weeks ago. I should write reviews on them (the BMW X2 was the nicest).

 

[jsimon7777]

I am tempted to get one. My aux currently shows 15.5v (probably charging then), and a failure would be under warranty, but avoiding a dead car and a dealership visit is worth the money.

 

[rcomeau]

I am tempted to get one. My aux currently shows 15.5v (probably charging then), and a failure would be under warranty, but avoiding a dead car and a dealership visit is worth the money.

The service tech was pretty adamant that the Exide EK151 was not the exact battery and that any substitution will confuse the software that manages it. I am not saying he was tight (might be someone saying to someone saying to him), but he thought changing for anything other than the genuine Jag battery was not advisable. In my case, I have been waiting for over 2 weeks for that mythical genuine Jag battery. The day I get the car back, I will check what was actually put in. If I see a Land Rover logo, I'll have a good laugh (or cry, not sure what it will be)...

 

[Ayepace]

Jaguar and Land Rover owners equipped with this auxiliary "stop start" battery have been putting the EK151 in for many years now. Here's a picture of earlier part number JLR battery. They changed their part number systems after this was labeled. The one in my car looks like this.

In an earlier thread, I had also identified Deka Aux14 battery as a replacement. It will require M6-to-post adapters to attach the cables. These are the posts that come with the Braille batteries.

There's really no such thing as a different battery between J and LR.

 

[rcomeau]

Jaguar and Land Rover owners equipped with this auxiliary "stop start" battery have been putting the EK151 in for many years now. Here's a picture of earlier part number JLR battery. They changed their part number systems after this was labeled.

In an earlier thread, I had also identified Deka Aux14 battery as a replacement. It will require M6-to-post adapters to attach the cables. These are the posts that come with the Braille batteries.

There's really no such thing as a different battery between J and LR.

I agree that this is the case, but they were pretty adamant about it. I did not feel I was in a position to call them on it and they were just repeating what they were told. They are getting calls from multiple desks within Jag to get this service done but the holdup is the parts dept. for some reason.

 

[rcomeau]

I agree that this is the case, but they were pretty adamant about it. I did not feel I was in a position to call them on it and they were just repeating what they were told. They are getting calls from multiple desks within Jag to get this service done but the holdup is the parts dept. for some reason.

It occurs to me that both times I jumped the vehicle after it went dead, I was accessing the battery on the left side when facing the hood from the front. Jumping it worked. Can someone tell me if the two are connected in parallel (so jumping one is effectively jumping both)?

 

[Trielectric]

Since I had a Honda ST1300 that I put a Lithium Iron battery in and had great results including faster starting and no maintenance and was still going strong 5 years later when I sold the bike, I thought I would throw something out about Lithium Iron Batteries (lithium phosophate.). I also replaced the 4 lead acid batteries in my Craftsman electric lawn mower with 4 Lithium Iron batteries. It sounded like a jet engine when 1st starting it! Mower was incredibly lighter. Bad, I had to manually balance the 4 batteries at the end of the Crastsman Charger's stopping point. Shorai has a battery for our Jag. LFX14A1-BS12 $159.95 list price. Shorai dimensions: L148mm, W 66mm, H105mm, <2lbs vs Jag batt:. L150mm, W90mm, H145mm, > 2lbs. Only bad thing I see about it is the Shorai battery does not like >15.2volt and it sounds like the Jag's battery charger may have some drift, which may be causing the early battery failures. And Jaguar would probably highly frown upon it. The only reason cars are not using them now, is the price.

 

[jsimon7777]

I would think any auxiliary AGM battery with similar specs and the right posts would work just fine. AGM is only necessary because of the charging system's software.

 

[[email protected]]

You have it right.

Big traction battery on the bottom of the car (part number varies by VIN) that powers the whole car at full power on. It costs $38,000+ and requires a lot of work and specialized equipment to replace.

Up to MY20, they have two batteries in the frunk area. The larger 99R/T4 flooded starter battery (T4K6642) on the right side of car and the small auxiliary 14Ah AGM battery (JDE32902) on the left (the purpose of this thread). Its voltage is displayed in WattCat (or equivalent), using https://ipace.herokuapp.com/static/param.html, or some people have added Bluetooth capable battery monitoring devices available at Amazon and other places. The voltage reported may show charging voltages at time (15+ volts). This is a good thing. Below 12.2V is a bad thing.

Starting with MY21 the small auxiliary battery has been discontinued and they only have the starter battery.

The TCU battery (T2R23864) is stored internal to the TCU as shown in the picture in the thread from dernotte. It is a battery assembly with two batteries. It should last at least 10 years. The TCU is located behind the left loadspace trim panel.

(Part numbers subject to change.)

So 14Ah AGM (JDE32902) battery is the one often failed, right? Which seems available to order online. In my case, the dealer had in stock or maybe they just replaced with something similar.

What about the bigger one? Mine is T4K11604, which show up at Genuine & Authentic Classic Parts | Jaguar Land Rover Classic Parts but not available. Some thing else (Jaguar seat Harness) showed up when searching for T4K6642. I am just worried about if a replacement will be available when needed.