Thanks for your comments. The local specialist does warranty work and yes I’d have to get it cleared with the warranty co first. I’d also have to pay first and claim back. I wasn’t aware the 3rd party warranty co sends out JLR engineers. I’ll ask them if that’s the case. My warranty is with JLR but as we know it’s a 3rd party co. I might be doom and gloom on main dealers in general but way too many bad experiences with different brands over the years.

I’ll have a chat with the stealer and the warranty co and see what they say. My car is dead so it would need to be flatbed to the stealer.

Thanks again

You did say extended warranty I presumed you meant JLR extended warranty? if its not, forget what I said  2018 SE SDV8 4.4 Byron Blue

Yes it is jlr extended warranty so it was interesting to hear of your experience and I’ll be talking to them about sending out a jlr mobile tech, thank you 👍🏻

Is it JLR extended warranty with the optional assistance package? if so, its Landrover assistance who you call and request a JLR tech they will ask what the problem is and if offered refuse the AA man. 2018 SE SDV8 4.4 Byron Blue

Yes I have got roadside assistance actually, so I'll talk to them about that - thanks for your help

update on this dead l405 - it's not dead any more.

it wouldnt start, but was showing 13v on multimeter. Jump leads under bonnet also wouldnt start. No electrics to dash or doors so couldnt get into boot or move electric rear seats. Infotainment and side steps power still worked. Checked earths all ok.

I ended up taking the rear seats out (very easy) to get into the boot to get to the battery.

Battery was 05/2014 so 10yrs old, presume the original. Probably should win a prize for lasting that long.

Swapping this cured everything.

Lessons learnt
- could have checked the battery date before, but had no real reason to - it had the low battery start now warning a couple times, and tailgate a couple times, but otherwise ok.
- get a proper battery checker to keep an eye (looking at the Topdon BT20 at under £20, but also run carscanner to monitor voltage)
- keep on trickle charge (which I was already but clearly the battery was very far gone)

Feels like a bit of a newbie problem having such an old battery, but posting up in case anyone has similar problems in future

IMO I think its worth changing the battery more often as everything works so much better when the car has a new one.  overfinch modified