So, these XK150 XK's / XKR's seems to be renown for Battery drain issues, low voltage, and causing havoc on the cars electrical systems. Sometimes showing weird lights on dash, limp mode, windows not working, or even the car not responding at all and then an hour later like nothing ever happened.

My question, and I'm sure there's loads wondering.. WHY THE XK? why not any other car?

Does anybody actually know the reasoning behind it? why is it the XKs seems to want to be plugged in to a CTEK all the time if left? Hell I've had around 50 cars and probably each one has been left for a couple of weeks straight with no issues on starting or electrical after, so what is causing the XK/R to have these issues? Is there an underlying problem that once sorted will fix this and not require being plugged in?

I'd be afraid of buying a new battery, and going away on holidays for 2 weeks and coming back to the car and said new battery no longer good?

 

The previous model XK8 (X100) is exactly the same. I don't believe that in either model it is down to battery drain issues for the most part. It's just that in modern cars, part of the design is that the car systems (usually through the ECU) monitor the condition of the battery and if the voltage at any point during the ignition and starting cycle goes below a point set by the design engineer for a particular period, then the car starts to register faults in several modules.

For some reason, Jaguar set a more sensitive voltage assessment than most other manufacturers. They must have their reasons for this high threshold but it does cause issues for many drivers. However, other manufacturers also have certain quirks. My Ford, whom Jaguar were part of when they developed their CANbus electronic control system, would monitor the voltage and if it fell below a certain level it would not even allow the starter solenoid to be activated. If the engine was already warm then even a very discharged battery might give you one chance at a start but the Ford system would simply shut down the starter system and that was that. Not even an attempt!

Richard

 

It's not as unique of an issue as you make it out to be. Most marques have the exact same problems and especially with exotic cars like Ferrari, Lamborghini, McLaren and so many more.

ANY battery which's defective or below proper voltage's going to have all sorts of issues which has nothing to do with the vehicle in which it's fitted.

Since you're citing Jaguar, of the 6 Jags I've owned, NONE have ever had battery issues not related to defective batteries.

 

Guys, switch to AGM.
My battery is 18 years old, made by Varta, no problems yet.

 

I switched to AGM even though the previous non-AGM lasted 8 years. However, I don't expect to get 18 years out of the AGM. That is scarcely believable unless the car is never actually used.

Richard

 

Before fitting my AGM I had lots of problems. None since. Seems like AGM is definitely the way to go.

 

Batteries come in varying qualities.
Electrical demands of the modern vehicle rely on the activation of modules which are voltage and current dependant.
And batteries do deteriorate over time.

I’m in the camp with GGG and JAHUMMER. (sorry guys, I misquoted earlier). There is no issue with the car. Its the avoidance of replacing the degraded battery that has you in this fix. (Translated: inefficient electrical power does not provide sufficient power to activate the modules)

And there are many battery technologies available. Some of my vehicles (like the xkr and the boat) run quite happily with a lead-acid. And some (like the LR4) need the higher capacity of the agm.

Cheers

 

Btw, found this that may be interesting to some:
https://techiescience.com/car-battery-capacity-in-mah/

 

Another AGM fan here.... using a Duralast Premium AGM for just over 3 years. Personally I think it is partially a battery quality issue. My last lead acid battery in my XK gave me endless issues even when kept on a ctek. I think it had some bad cells from the factory and over time, it quickly lost capacity.