In my case, once I removed and reinstalled the battery my top wouldn't lower and I got the luggage separator out of place warning on my dash. Tried moving the separator into every possible position but to no avail. I could tell it was in the correct position but for some reason the microswitch wasn't being triggered.

Scoured the internet for an answer and spent way too much time staring into the trunk to see if anything was amiss. Exasperated and feeling defeated, I was about ready to take it to a Jag specialist when I felt something small laying on the trunk carpet. A black U shaped clip! It has fallen out of the separator during removal. I put it back in the notch that aligns with the microswitch and it solved the problem! It's a fairly tight fit so I'm not sure how the little rascal got out, glad I found it and I hope this saves someone from going through the same frustration.

 

Well it finally happened to me…. drove the car stop and start all day yesterday and this morning….. no start. I do have the C-Teck tender but hey,nothing lasts forever. I have a question on the MT5 49/H8 battery mentioned in some of the prior responses. It does not appear to be vented, any concerns? Thank you.

 

Some are and some are not. The chain stores are notorious for not carrying the vent kit (some batteries have a different vent configuration and need an adapter) or even know what you are talking about.

The battery releases odors and flammable hydrogen gas when charging; you do not want that in the enclosed space of the cabin for health and safety.

 

Put my charger on the battery and after about 2 1/2 hrs apparently it was fully charged. Tried to start but no luck. Placed it on the charger again and it read 70% charged. Again, after a couple of hours it showed as fully charged but still failed to start car. After the 2nd failed attempt I noticed the battery went to 12.6 to 12.8V I guess its not holding a charge but I was assuming that it should have at least turned over. Oh and by the way, the C-teck tender showed green after about 4 hours of my failed 2nd start attempt after having charged the batterty. Should I see if it starts by "jumping" the car? I will purchase a new battery on Mon or Tue. Any harm in jumping these cars?

 

If you want to try a jump start, do it from a spare battery (or one taken from another car) - don't do it from another running vehicle. You can get some nasty voltage spikes which could damage the XK's electronics.

 

I was going to try jumping it with the battery still attached to my other car, just not with the engine running. Having said that, while in the garage, i heard the battery charger fan (left it on all night) kick in. Walked over and saw 14.4 - 6 V on the display….. went in and it fired up. Beautiful weather so took it for a little cruise, parked it and plugged in the C-Teck. Curious to see what happens tomorrow. Will definitely get battery checked out as it will prob need replacing.

 

Is the 'correct' part number the one WITH the A or the one WITHOUT the A?

 

If you find the old number (MTP-) then the A must at the end to identify it as an AGM battery.

The newer number (MT5-) does not have the A suffix, and is an AGM battery.

V

 

I will soon replace my still functioning battery in my '10 XKR. Planning to get an AGM one. The one thing I want to do is to keep the electrical system energized while the replacement is taking place. The main reason being is that I don't want to car to loose its smog parameters memories, which are required to pass the CA smog tests. In some of my other cars it took nearly a thousand miles of driving to "reset" those parameters after the batteries were disconnected.

Any recommendations for a plug-in device for providing voltage to the ECU while the change is taking place?

 

I don't think you'll be able to 'plug in' something, because the accessory sockets aren't really designed for the purpose. However, when the time comes to swap my battery, I intend to use a jump-start booster battery. I'll clamp the booster's croc clips onto the battery leads before I remove the leads from the battery; as the booster has a pretty substantial capacity, it should be sufficient to keep the car powered.

A useful hint from another forum member: use a wooden plank as a ramp to slide the old battery out & the new one in. Reduces wear & tear on your back.

 

I just seem to remember being told that a device exists that shops use for this purpose and they simply plug it into one of the 12 V power outlets. Again, my fading memory suggests that it was a 9 V device, providing enough voltage for the ECU to maintain its memories during the battery exchange process.

I do have several 12V chargers, jump starters but, have to make sure that they are not putting out a voltage which is too high and potentially fry the ECU. Those chargers are designed to put out 13-14V when they sense the impedance of a battery. Without it, the output voltages can approach 20 VDC.

 

That's why I'll use the booster - it's just a compact 12V gel cell battery in a fancy case.

Those plug-in memory savers work if the accessory/lighter is relatively directly wired into the main 12V supply. In the XK, there's relays and control modules in the way. I'm not saying that I know it won't work; it's just that, from what I know of XK electronics, trying to feed 10A or so of power into the car via the lighter socket (because that's what it draws when it's unlocked) doesn't look like a good idea.

 

Good points, indeed!

 

Had the battery in my '08 Xk replaced last Friday, and went with the recommended (in this thread) AGM battery from Interstate. Thanks to the members who recommended this battery and type.

Quick side note: I went to explain the battery reset procedures to the Firestone guy, and he just smiled and said, "We leave 'em running to avoid having to go through that mess." Apparently, not his first Jaguar rodeo. The swap was seamless and all electronics are performing flawlessly, so my trepidation as this technique was unfounded.