UPDATE #1: Battery arrived a day early! That was a mental relief. I had to laugh. Heavily labeled: "Team Lift". Where's that team to help me put it in the Defender??? It was a log easier getting it in. Here's what I did going the other way and lessons learned.

1. I set it on the edge of the tray to get things ready.
2. Place the JLR Approved Part #XPEN51V-SOC onto the end of the red/positive/charge so that I wouldn't accidentally ground it against something. Likely not needed, but I wasn't taking chances.
3. Plug in the breather tube on the front (towards the engine side) BEFORE I put the battery in.
4. Spend 5 minutes gloating that I FINALLY did something in a good order before having to redo everything because I forgot that breather tube.
5. Using my 10mm socket, attached the red/positive/charge terminal good and snug and down and tight. Didn't over tighten for once.
6. Slid the battery into the tray. It went in SMOOTH. No big thumps. Another minor miracle.
7. Took off the sock and discovered that the red/positive/charge cable is THICK and doesn't bend much. The terminal was rotated clockwise too much. DANG. So, I reached into the "Wood Beast", loosened the terminal until in allowed the connector to properly seat and then retightened. Might have to rethink that move next time.
8. Using the 13mm snugged up the tail of the red/positive/charge cable.
9. Using the 10mm rachet & extension, returned the battery tray lock/holder/support thing. It was a fiddly mess to get both holes lined up. And the threaded part of the black unknown threaded post goes up in case you want to know.
10. Plugged the BMS into the side of the black/negative/ground terminal.
11. Gloated another 10 minutes thinking I did something properly trying to forget the tail that was out of whack.
12.Seated the black/negative/ground terminal after saying the proper prayer to Lucas and every other Diety I could think of.

As soon as I plugged in the black/negative/ground terminal the Beast came to life. I mean EVERYTHING. It was as if I hit the on switch with my feet on the floor. On without cranking the engine. I quickly ran to the pilot's seat and started the Defender. It was a weird double tap to get it started. But it started fine. On the dash it gave me a "SOS System limited functionality" error that I cleared. I'm hoping it means that it fried all the tracking telematics, but I can only hope.

Then I let it run for an hour. I'm still waiting. As soon as it does, I'll turn it off, step away for a few minutes and restart it hoping that "SOS" is gone. Then I plan to put it on the CTEK overnight. II'll give a second update tomorrow while I pray that I don't have to give a third a few days from now that the dang thing died on me again....


Where's the Team to help me Lift?!



Ready to slide into the tray with the proper protection applied to the tail of the terminal.



SOS. I figure it will go away. I'll update if it doesn't. You'll know when I have to make a service appointment or go to DefenderNet to find out the right CCF code...

 

UPDATE #2: Ok, the hour is over. Started back up like a champ. Here's some things to note:

InControl login had to be re-entered.
Radio stations were preserved.
GAP settings I've made are preserved. Bonus round: the AutoStart/Stop that I used the GAP Tool to always remember that has been flaky now seems to be solid/working!
The Dash shows the Yellow Check Engine light but when I go into PiviPro, it reports that the vehicle status is fine. I've heard it settles itself after 30 mins of driving. I've got a shortish road trip planned tomorrow which should settle it out.
Surprise! I was offered a software update for 4.2. I was super anxious to add this onto everything, but what the heck! Live on the edge: I approved the download/setup and will let it do its thing while the CTEK does a battery refresh. It would not update with the hood open, so I closed the hood on the CTEK. I don't like doing that, but now both the battery recondition and the update can both occur.
Happy Moment: the CTEK detected the battery. And it started right back up. I let the CTEK do it's thing.


Dash showing (i) and Yellow Check Engine. The (i) is for the software update that's now ready. Surprise! Hoping the check engine clears.



PiviPro gives it a clean bill of Vehicle Health. If this and the check engine don't align, I'll plug in the GAP Tool to see what it says.



Surprise! Software update ready. Not sure if it was triggered or just a coincidence.



On its way to being fully loved.

 

Are those Voyager sliders with the optional tread plates?

 

@nashvegas - They are Proud Rhino's from Lucky8 with the optional tread plates. They were a BEAST to install for a lone shade tree mechanic. But, I muscled them in there for an old guy. I had them Line-X'd before I installed them. Love them. There are some lessons learned when installing so do the research (or ask) before you do it.

 

UPDATE #3: Last night, I interrupted the CTEK to take my son for a ride to get ice cream and me to get put some gas in. The first trip was >25 mins and the SOS warning, (i) and yellow engine light came on. After the second trip of about 15 mins the yellow engine light went away and hasn't returned. I'm pretty sure that was the BMS resetting.

I asked my favorite AI search (perplexity.ai) about the SOS warning. To my supreme pleasure it told me that the warning was because the Telematics battery was dead. Woo hoo!! There is a silver lining in this cloud. The PiviPro nav works. The Defender app is tracking the vehicle. I don't know which telematics battery is dead, but if it's the secret one that has all the tracking "crap" on it, I'm in heaven and have a glee every time I clear the warning. I'm sure I will get tired of pressing that button like the autostop, but by then I may be close to letting a dealer deal with their battery.



This morning, the CTEK was lit all the way to #7 - "Float. Maintaining the battery at 100%". Just what I wanted to see. We are good to go now. If I post an update #4, it didn't go well...

EDIT: I just watched a video on replacing the battery in an Evoque. Seemed straight forward. He said that if the vehicle sits for a long time and it goes dead, drive it for an hour or so and it will recharge. Guess that's me. I looked up the part # in case anyone ever needs it (LR046049) and the diagram (parts diagrams are rough) showed it roughly in the dash area. No WAY am I going there for this. Also, on e-bay the part was $89, in the UK it seems to be 59 pounds, and I could find it for $58. My favorite online shop (West Palm Beach JLR) said it was unavailable. Here's to hoping it just recharges itself.

 

Great info in this thread. Thanks @GrouseK9

One question. Can you clarify how to carry out a BMS reset with GAP. I'm going to see if I can figure it out too but thought I'd ask first. I've had my battery disconnected when I was doing some wiring. Overkill, rear lights I think. Never bothered when I was adding my ditch lights. Go figure. No fires or socket welding so far.

 

Fortunately, haven’t had to figure it out! It resent itself after a couple rides. All in less than 30 mins. Only thing outstanding is the telematics battery. I’m trying to see if it will charge itself per the Evoque replacement video said may happen. If not, I’ll eventually do a dealer visit before the warranty is up next year.

 

Great, another battery located in a place you have to cut the car in half to get at. At least it is reasonably priced. The secret backup battery for my airplane is also located behind the instrument panel, but is naturally, 100 times more expensive. On the plus side, turns out it is made up of Gates Gel Cell individual cells. So I just replace dead cells. Luckily they are the same ones used in railroad backup signal systems. We kind of have a major railway maintenance operation going on here and even Batteries Plus carries them.

What didn't work afterwords is interesting, but kind of expected. The Telemetrics thing is really a seriously nebulous system. A faulty cable held mine up in port for 45 days, then again it was held at the dealer, for apparently the same part another month. Turns out the cable was made in Ukraine. There was apparently an excellent cable fabrication factory that supplied a whole host of automakers that bottlenecked several lines. VW apparently had to shut one factory down because of the disruption. I certainly wish you good luck on the little battery coming back to life, I hate working in the dash, let them do it. I just wonder if there mightn't be another tiny battery that choked and is waiting to rear its little electrical head. I would have been happy if they delivered the car with the system not working, but it probably hooks into the rest of the system and provides some kind of feedback rendering you vehicle inoperative for a silly reason or another. I asked the service rep what the system does and really didn't get a coherent answer. He covered some things but completely left out others, which I subsequently discovered. Still really do not have a complete picture. It will probably now have your pizza deliveries go to another address until the battery works again.

 

Lol! I've never lived anywhere close enough to a pizza delivery shop. Maybe now one WILL start to deliver.

When I return home, I'll probably root around in the Workshop manual because I'm just OCD when it comes to things with my gear/equipment. If I find anything interesting, I'll post it here.

EDIT: Well that's not too bad! Seems that the Telematics Control Unit (TCU) that has the battery in it is located in the left trim of the loadspace (aka, boot). Here's a link re: all things TCU (Link). I'm pulling out ALL my favorite research sources for this one.

This also says that the battery is rechargeable. Likely need to just drive the Defender more to charge it up. Then again, maybe that's the little sucker that is bleeding the CRAP out of these vehicles. Tells you ("someone) where the vehicle is at all times and what it's doing. Likely never goes to sleep.

"The TCU receives a permanent power supply from the Battery Junction Box (BJB) through a fuse in the Passenger Junction Box (PJB)."

"The TCU charges the battery when in Power Mode 7 (engine running). The charging function is controlled and regulated by the TCU software."

 

Well I can only pray my wife's battery in her Evoque does not die, then again it too has the super picky down to tires and rims warranty (the tire and rim coverage has already paid for itself, two to be exact). No that location looks actually simple to access, aside from the fact you will consume around 20 plastic fir tree fasteners that will inevitably break and be a hard to source from anyplace but JLR, at $5 each, or .02¢ from China, with 22 weeks delivery and you have to buy 200. Like my and perhaps two other people's lifetime supply of engine cover rubber bushings.