My TDV8 has decided it will only start intermittently. Even after a long run it might or might not start. It gives a "click" as if the battery is dead, then might start after two or three tries. Jumping it always starts it, suggesting the battery is the problem, but it can be fine for days then suddenly will not start. Local garage (not RR specialist) can find nothing wrong with the battery or electrics.
Anyone any ideas?

I had a problem with a starter motor that did exactly that. Wouldn’t start, hook up the jump pack; and away we went.

Turns out it was nothing wrong with the electrics, and hooking up the jump pack only gave time for things to "settle". I think I read another post on here that had exactly the same problem.

Sounds like the usual tdv8 starter problem. had mine replaced under warranty and no problem after. Agueroooooooooo. 93-20
I swear you will never see anything like this ever again....watch it..drink it in.

Possibly also a loose connection onto the battery.
I had this a few months ago and the car would appear totally dead, or just click, then a wiggle of the earth connection would sort it out. Worth giving them a tighten. Got - 2017 SDV8 Autobiography in Loire Blue
Had- 2008 TDV8 Vogue SE in Java black
Had - 2007 S/C in Stornoway Grey

Yes, I had a starter motor replaced when the car was about six months old with a similar issue but this is far more intermittent, and always works with the jump pack.

I had similar, intermittent non-starting, initially no click when starter button pressed, but after a while it started clicking, battery fine, was defective starter motor, it was replaced and now fine again. The problem seemed to involve the motor overheating. If you got a new motor in 2012/13 it may have become similarly defective. Only Range Rovers since 1988

I have a petrol but had a similar problem with my supercharged replaced the positive lead and problem solved - sometimes the leads corrode internally also worth taking both terminals off the battery cleaning and reseating so they are tight - could be poor connection and putting the jump pack on makes it good