So
A couple of weeks ago I posted about possible battery issues regarding my 4.4 TDV8 HSE 71K
The JLR dealer I bought it from came up blank. Basically because the battery issues only 17 months old, & still under warranty.
On Xmas Eve, I was locked out of the vehicle. Drove car 10 miles to Physio…. Left it for 40 minutes… Dead as a Dodo.
Got into vehicle using emergency key.
Alarm activated….
Opened bonnet …. Went nuts.
SMART KEY NOT RECOGNISED on dash.
Placed flat side of key on drivers panel, where the engraved lines are… nothing.
Tried my NOCO X Boost, didn’t want to know.
You could start a tank with it!!
Call AA.
12.59 vols across terminals.
Checked all grounds on body, Engine and gearbox. Checked main earth. All good and same voltage.
Conclusion… battery issues fine.
Go for hard battery reset. Operate Key as soon as power pack is grounded, and it operated, and started immediately.
Checked fault codes.
All Canbus related , but general electrical failure.
Drivers door features heavily.
Entered service mode on iiD, and register new battery.
Procedure shuts engine down, and registers. Restarts. Drivers and passengers doors & windows re engaged.
Drove vehicle around for 3 days, never locking with the fob. Manual lock….
If locked manually, Immobiliser is not initiated.
Pain in the arse but no problems, whatsoever, and zero fault codes.
Today… used key fob.
On second opening…. Just a clunk from starter ( 17 months old ) , then dead as a dodo.
12.45v across terminals
Should start
Fault codes
Reset battery…. As new. Manual locking …. No problem.
Each time it fails…. It loses all memory, going back to 01/01/2009 three years before it was built.
Personally…. Being a bit long in the tooth….
If the alternator is charging …. It is 14.7v
The earths are good, I would always suspect the battery.
What do you guys think??

Is it an AGM battery? Read somewhere earlier that the digital dash models require this and nothing else lasts.
No idea why given your battery voltage but that was the same in the one I heard about earlier.
Hope this helps. Rehab is for quitters!!!

RR 2007 3.6 TDV8 Java Black *
RR 2007 3.6 TDV8 Zermatt silver *
RR 2000 P38 4.6 Met red *
Mercedes 300TE 4-Matic *
Jaguar 420 (1969) *
Nissan 300Z
Citroen XM 2.5TD X 6
Bentley Continental R
Hydrocon Highlander
Hydrocon Hamilton
Hydrocon Huntly
Am told the ones with a * are to be offered for sale! 😳

Departed
LR 1992 110 2.5TD
RR 2000 Holland & Holland 4.6 LPG
RR 4.2 Supercharged with LPG, Vogue SE 2007 Buckingham Blue
RR 2002 4.4 V8 Zambesi Silver