I understand the S-Type shuts down somewhat sooner than that table. Whose table is it?

A drain along the lines of 30mA means a used but viable battery should be OK for a long while and those cars where that isn't true just have a fault that ought to be fixed IMO. (Though it may be easier to just use a ctek etc.)

 

Readers should take a look at the BMW engines in Jaguars
thread in the F-Type section.

There is a link in there describing how BMW has instituted
a CCP which stipulates that the batteries on vehicles using
the N63 V8 be changed at every oil change. The OCI was
15K miles and has been reduced to 10K miles.

They run their batteries in a similar manner to that found in
the X150. That is, coulomb counting so they can squeeze
out more fuel economy and full throttle acceleration.

0.10 extra MPG might be great ... except when you then pay
for a battery minder and the juice to run it.

Being green might be great ... except when you have to replace
the battery more frequently.

Unlike Jaguar, BMW has at least acknowledged the problem to
some limited degree. But once the CCP terminates for an owner,
the cost of an oil change skyrockets due to the inclusion of the
cost of a new AGM battery.

Now, how is it that the X150 suffers from the problem while similar
powertrains in the F-Type and XJ do not?

This is another indicator that all is not right.

There is a battery life design goal known by the name of
the airport parking test. A vehicle is expected to be able
to sit at an airport for four weeks and then start successfully.

It is clear that some X150's would have a hard time passing
the test.

Not very many airports have provisions to plug in a C-Tek
unless you also own a hangar there.

 

The car should hold a charge for 4 weeks if double locked and sitting for four weeks, *if* the battery is fully charged when you park it. If the issue is with the charging logic like the BMW, the batteries tend to discharge more than they charge, leading to shorter battery life and eventually a call for a tow truck. I use my car on the weekends, and I have no problem plugging it in, but it seems like the drive for .1 more mpg might be the culprit. I think I've only seen one post in this thread where the dealer diagnosed a module as "staying awake" as the culprit. I think I read some others that had issues when plugging in readers into the obd port. The poor charging logic sounds like the most probable cause of low battery warnings for most people.

Good read :
http://www.forzacomponenti.com/docum...nders%20V3.pdf

 

Jaguar's, from their XE workshop manual on Topix.

 

Interesting, thanks. Looks like even their own people are uncertain how long to wait so put longer in.

 

I have not read every thread but am familiar with this one. Wouldn't it be the easiest fix if the car does return home regularly and does not travel long distances, to just keep it attached to a CTEK or equivalent charger? I have no idea how old my battery is on my 2010 but after 2 1/2 years of ownership and keeping on the CTEK charger when not being used, I have not had any issue with starting. In addition, before I purchased the car, the car sat at the dealership for weeks at a time if not longer for test drives etc without locking doors or charging without a single incident of a low charge battery.

 

It's not just a good read; it's a MUST read! Absolutely the best layman's explanation of automobile battery technology that I have ever read! The only thing that I take exception to is that the author recommends the Deltran "Battery Tender Jr" brand of battery maintainer (as well as CTEK). Check the Battery Tender, Jr. reviews on Amazon and decide for yourself. Like others on this Forum, I'm a fan of CTEK brand battery maintainers.

 

Ok??? They seem pretty good to me. Probably the highest rated Anything I've seen on Amazon with over fifty reviews. I certainly didn't expect that. Of course, the CTEKs all seem to be right there also.

 

Good article and similar to others I've read. This is only part of the equation as the charging system has evolved to the point where the state of charge , the type of driving and charging rate are unlike the days of old where a straight 14.2V regulated charge doesn't happen. In the Jaguar world this change took place in the 2010 MY . Look up articles on computer controlled charging systems and it may surprise you on how they function.

 

Interesting article, thanks. It confirms my suspicion that switching to an AGM battery was a good choice for my car usage pattern:

Driving Style and Needs
What is your driving style? If you make frequent short trips, there is less time for your car to recharge the battery. For this style of driving, an AGM battery has a distinct advantage over lead-acid batteries.

Battery Tenders
If you have an AGM battery, the use of a battery tender is less critical, but is still highly recommended.