Last night after getting home from dinner It struck me funny as to why is there more drain on the Jag battery then other cars with the comparable accessories. I have a 2010 Lexus and it has as many features as my XKR and yet I'm still on my original battery. I drive this car maybe 2 times a week (42K miles on it) and it sits in the garage unlocked. Now I look at my 2008 GMC pick up and it has 47K miles on it and still has the orig. battery and I drive this the other days of the week. I wonder if anyone either the factory or some independents ever ran some type of evaluation to understand why there is so much of a difference. Just some sky blue thinking.

 

Its no secret... Jag designed the computers to do as they do without thinking it out thoroughly as to the drain (which is significantly higher if the car is not locked or if the key is in proximity). You're also comparing your 2007 Jag to newer 2010 Lexus where the power needs of the computer systems have come a long way in a short time. I doubt it was a common problem to be dealt with prior so this turned to to be a mistake. Jag was designed to be a road car with exceptional performance little thought was in the infotainment which is now obvious in both how antiquated the navigation is but also in its abhorrent power drainage.

The sad part I find, which is also not uncommon, is that they are aware of the issue now but most dealerships will ignore the facts and prescribe new batteries, costly detailed scans, etc and never really address what is wrong. A maintainer will usually remedy this as most here have found. What I find also both puzzling and sort of sad is that there are a few here that are VERY adamant about the idea of not using a maintainer, that "I'll sell the car before taking that route", etc rather than spending $60 or so bucks for something that at the very least is a good idea anyway and may well add significant longevity to the battery and perhaps eliminate being stranded... to each his own.

 

The temperature where you live might have something to do with it. I live in a warm climate, I had one Jag for 5 years and no battery issue, another I bought used but kept it until it was 5, no problem there either. But I use my Jags as daily drivers, maybe 10km to work and then similar home each day.

But then my missus went through a volvo battery in a year and a half, the battery guy said the short school drop off trips (pretty much all it was used for) kills them very quickly.

 

My Jag is a 2012 so the Lexus is 2 years older.

 

Since you seem to be struggling with the concept, look upon it as a science experiment: Take 20 XK owners and give half of them battery maintainers to use every night. After 6 months you get them all back together and find that the ones who had maintainers had no electrical glitches so they smugly pat each other on the back and declare that you can’t own an XK without using one.

You then turn to the other 10 who didn’t use maintainers and find that 7 of those had no issues and 3 did. The very fact that there were 7 who had no issues proves that you don’t actually need to use a maintainer, it is a simple fact! The 3 who had problems were then found to either have an electrical drain that needed fixing or a battery that needed replacing or generally abused the battery by leaving the touch screen on for too long with the engine off or doors open, etc.

I have owned around 20 cars since I started driving, 7 of which have been Jags, and I have treated them all like normal cars. I expect to be able to just jump in them and go so until Jaguar produce an Electric or Hybrid car I have no intention of plugging mine in every night.

I do have a CTEK and used it when I first bought my XKR because of the electrical glitches I was getting but since changing the battery I have had none so the CTEK stays in the cupboard.

Of course all of the above only applies to daily drivers though. If I had a fleet of cars like some members of this forum do and only got to drive the XK once or twice a month then I too would probably use a maintainer on it but for now I drive the car 4 or 5 days a week, don’t lock the car at night, only do short trips (< 5 miles) and have no issues. What is puzzling or sad about that?

 

What's so puzzling or sad you ask? Perhaps your arrogance or projection of using the term smug? Just a guess and a start...

You try to pose a claim of taking several Jags to prove a point knowing full well the test won't be done so it's a worthless claim, as is your stance. You brought it up would you mind showing us what those results were? Clearly those cars all started with be batteries and we're driven the same miles right? That would be the only way you could somewhat come to a sensible conclusion but somehow you probably just blew smoke right???

I don't own a Ctek however I do own and often use another brand. They're are MANY here who had issues that through their usage have found it resolved the common corporate problems... whether you anecdotely have not or not yet experienced these problems does not mean they don't exist or can be relieved using a good maintainer. Good for you that you haven't but name calling those who suggest their usage hardly is helpful. If you don't like the advice, don't take it but know that there are many who have found it helpful and a far lesser number who fell differently like yourself.

 

We only hear about those with problems.

My STR has at least as many modules etc as an XKR and the battery is OK after 8 years so far. (And I even managed to run it down twice, before realising what an idiot I'd been both times.)

I leave my car unlocked in my garage when not in use.

I expect newer cars will get more modern designs of modules and they tend to be lower power. (But more are fitted...)

(I wish smartphones lasted longer before needing a recharge.)

 

I too have never had a problem with my battery, I drive it usually 2or 3 times a month, but have had it laid up for up to 8 weeks over winter without charging and it has always started up first time. I'm not saying there isn't a problem with other peoples cars, but you can't say it's a problem across the board as there are obviously cars that are fine.

 

I'll bet there was a screw-up when your car was built, somebody forgot to install the 'battery sucking circuit'. Probably got fired for that.

 

↑ They forgot to install the BSC on my car too. My car battery is over two years old, and my 2007 xk is used on weekends only [every other weekend to be exact]. I do not need use a battery maintainer because all of my electrical components are working correctly. It is my position that if you do need to use one, then you have a problem that needs to be fixed. But that is just my opinion.

 

Did the factory switch from conventional "flooded" wet-cell batteries in the 4.2L X150 models (2007-2009) to AGM in the 5.0L models (2010-up)?

My 5.0L XJ has an AGM battery. I'm not sure if all 5.0L models are AGM, but I suspect that they are. Anyone know for sure? Or is it just the 5.0L with stop-start? (2013-up)

 

I hope nobody's suggesting that a car needs to be plugged in each and every night. I only bother if the car won't be used for periods of two weeks or more, and that's probably too conservative.

 

My BMW 650 had the same issue with battery drain, some had it bad, others were fine. It is an exact duplicate of all the discussions I see on the Jag. Lock your car in the garage, don't have the key nearby, etc.

While I never had excessive drain like some did on the BMW or here with the Jag's I did experience short battery life. BMW actually has it in their manual that those with an "unfavorable driving profile" (short trips without any higher speed) will experience battery issues. My Wife fell in that category as she has a 10 minute trip to work in stop and go traffic. We didn't experience frequent drain and the associated electrical gremlins but did see short battery life. The battery died every couple of years, it should have lasted 5 years.

I top off the Jag battery once a week with my maintainer, just in the hopes that the battery lasts for a longer period. Sometimes I can go two or three weeks without putting it on the maintainer and I experience no issues at all.

 

I wouldn't say it is necessary but up to each of the owners. As for me I plug mine in after every usage because sometimes there is a week in between use. Also as I park my car on a lift it's not a problem plugging it in while putting it up in the air. No harm , no foul.

 

I connect my CTEK MUS 4.3 to the Jag XKR "every time" it gets parked in the garage, takes less than 5 seconds to connect.

I see no reason "not too" with my quick connect plug and play, except for laziness.

Click the image to enlarge, click again for full screen.

..

 

And mine is a 2001 with no problems.

It seems to be a problem with the X150 and not
for example the X350.

Battery maintainers are a bandaid that I feel actually
contributes to the early demise of the battery.

The real problem is the implementation of the coulomb
counting in search of improved fuel economy and full
throttle power.

 

My 2010 XK has a 'wet cell' not AGM. The battery was replaced once, as far as I can tell (Jaguar printout, purchased car used). Based on this and other threads, I checked with 4 different Jag dealers in 2 different states as to the correct battery (hey, I need a new battery, what do I get; they asked for the VIN, etc), and the response was wet, not AGM.

 

There's a world of difference between 'I do it to make me happy' and 'I do it to make the car happy'.

Kinda like buying boutique brand engine oils when there's no evidence that it makes any difference to the car.

 

You seem to like arguing for the sake of arguing. As you can see from the other responses there are others like me who don't feel the need for a battery maintainer and don't have issues.

The point I was trying to make with my imaginary science experiment (although it does reflect real life on this forum) was that if even one standard XK that is used reasonably regularly can be owned with zero electrical issues and without the use of a battery maintainer then they all should be able to. I can't speak for the 5.0L with the BMS but mine certainly can and from the sounds of it so can others and mine gets particularly abused due to the sort trips and being left unlocked overnight.

 

They do seem to be acknowledging the issue. The attached table shows that the later models have a shorter shutdown period and lower drain than the X150.

The issue I seemed to have before I changed my battery was more to do with the battery being unable to satisfy the needs of the electronics starting up. The fact that the old XJ's and XJ-S's had a longer shutdown period and drain seems to back this up. The touch screen in particular on my XKR would hang on the logo for 5 seconds or more before I changed the battery whereas now it is only shown momentarily. I don’t know whether that is due to AGM technology or just having a tired battery but that was the only clue there was anything wrong. With previous cars you could hear that the battery was struggling by the speed the engine turned over during starting but the electrical glitch occurrences with the XK seems to start well before you get to that stage.

The difference between the locked and unlocked shutdown periods is why people recommend locking the cars but mine seems to cope without me doing it.