Battery cell replacements are a H441 safety issue recall and nothing to do with the 8 year 100k mile warranty or extended warranty, other than the dealers go through the warranty procedure to make a claim - there's a few threads on it.
What model year car is it?

Jaguar

osh.jaguar.com

 

Battery cell replacements are a H441 safety issue and nothing to do with the 8 year 100mile warranty, other than the dealers go through the warranty procedure to make a claim - there's a few threads on it.
What model year car is it?

Model year is 2020 I bought the extended warranty with the understanding that I could get cell replacements, but today my service rep' said it wouldn't be covered after manufacturer's warranty ended. Good news if this advice was incorrect...

 

The extended warranty is clear that there is no coverage for the traction battery.

However as mentioned H441 is the route. However you can probably expect pushback.

 

There is, in fact, coverage: According to my extended warranty booklet the following text confirms cover for the traction battery (up to 100,000 miles/10 years):

"...While the manufacturer's warranty for the electric vehicle
battery is in place, that will take precedence over this
extended warranty if You need to claim for a sudden and
unexpected failure.
Charging and discharging a battery will cause gradual
deterioration of the battery over time. This warranty covers
the main Vehicle battery for sudden and unexpected failure
to hold its charge effectively. Gradual battery deterioration
is not covered by this warranty...."

 

There may well be pushback, but the fact is, the car only charges to 72% and the dealer says it needs a new cell, that is a safety recall and will be free of charge at any mileage. If you do a search on here and read relevant threads there are others who have had cells replaced free of charge well above 100 k miles.

 

Extended warranty schemes are essentially insurance policies. As we witness EVs racking up impressive mileages and not generally suffering from significant battery degradation, we are likely to see warranty providers (other than OEMs) trying to prise ££££ out of us for continued battery cover. For example, Opteven, the company that until 2024 provided JLR Approved warranties in France are already publicising extended battery warranties:

Vérifier l'état de santé de la batterie haute tension de votre VE (in French, so far no equivalent page on their UK website)

 

The question I have is what to do when your car reaches 100,000 miles ? You can no longer buy extended warranty (essential, in my view) and the battery is no longer under warranty. Mine has done 78,000 miles - and I love the car and would like to keep it, but it seems it becomes a write off if anything serious goes wrong after 100,000 miles due to the cost of repair.

 

Cost of repair is certainly an issue, but the worth of the repair is the additional use it gives going forwards.

 

That depends on your appetite for risk.
My wife’s Tesla is 11 years and approximately 100 k miles young and is clearly well out of warranty. Yes, replacing the battery would be more than the car was worth. Replacing the engine or gearbox would cost more than a lot of ICE cars of similar age are worth as well.

 

There's not really much need to worry about 100,000 miles - It's not clear it's been an issue for anyone as the batteries dont decay that much.
The H441 module issue, isnt mileage dependent so that should cover faulty cells beyond 100,000.
The other fault is high voltage insulation but that seems to be pack wiring rather than cells and ought to be caught while still within the 100,000 mile warranty.
Just enjoy the car
If you're really unlucky you can buy a pack from ebay from under £4k and find someone local to fit it. It's not known whether it would need coding or swap over the control modules.