last April I started having low battery issues and had to jump start the XJR twice if it sat for 2 weeks or more. The battery appears to be the original 2004 battery. In a post here, everyone seemed to agree it was past due for a replacement.

For a while, driving the car at least every 2 weeks or so seemed to keep it going, but not so much any more, and I had to jump it again - and a week later it won't start again.

So I want to change out the battery, and I'd rather not pay the dealer $600 to do it (that's what they charged me for changing an X-Type battery a few years back.)

I have a trickle charger from Harbor freight (but haven't been using it), and here's the question. If I hook the trickle charger up to the battery cables while I swap out the old battery for a new one, will I be able to swap out the battery without causing problems? I read about radio codes that have to be re-entered and other complications I'd rather avoid - so I'm hoping that using the trickle charger to maintain power while I quickly move the battery terminals to the new battery is a safe and effective way to do this. Right? Wrong? Any advice?

I believe I have the radio codes, and buying the new battery is about $200 at Autozone down the road. They only seem to have the Duralast brand, which they say fits the car, and its got 900 cca which seems to be the same type.

 

I have a 2005 XJR and have disconnected the battery for electrical work several times with no problem. I did not have any problems with the radio nor did I have problems with losing any settings for windows etc..at least that I know of. I also use a CTEK battery minder all the time.
I dont think connecting it to the terminals while removing the battery will work. Someone might correct me here.

 

Other than airing your tires to the proper pressure, replacing the battery must be the easiest DIY project you can undertake. In my car I always disconnect the negative battery post when I work on the car and never had issues with radio codes etc. If you absolutely want to preserve the ECM's memory while changing the battery, you may consider keeping the voltage on the cables while you change your battery with something other than a Harbor Freight trickle charger. Any charger that has a supply mode setting (such as a - I can attest to this since I own one) would do.

 

The only thing you need to do is take out the old BTY and put in a new one. The only thing you'll need to do after that is reset the windows and any child can do that...........


cheers........

 

Ok, three senior votes for "just do it" - so I guess its no big deal. (I guess reading too much in the forums leads to unfounded worries. I've changed a dozen batteries in other cars I've owned).

Hadn't thought about the windows. Looked for reset instructions and this was all I found:

start with the drivers window and push down until the window reaches the bottom. Continue to hold the button down for 3-5 additional seconds. Then, push up until the window reaches the top. Continue to hold for 3-5 additional seconds. Auto up/down should now be trained. Repeat these steps for all other windows. (caution - don't exceed 4-5 seconds as the window motors have a thermal fuse to protect against burn-outs due to jammed switches.)

Simple enough.

Thanks everyone.

 

I suppose you could run the trickle charger thru the cigarette lighter? This should keep the system charged.

 

May well be isolated with ignition off.

 

Hi MeatBag,

I changed the battery in our '04 XJR with no power supply attached and had no problems. I didn't have to mess with the windows and our radio apparently has no code requirement. Disconnect the negative battery cable first, then the positive. Before connecting the new battery, clean the cable terminals with a battery terminal brush.

Cheers,

Don

 

I picked up a new Battery at the Auto Parts store for $199 (its a Big F'er) and installed it myself. Everything works normally, no Radio codes required. Since the window memory reset was child's play, I went ahead and did it.

 

yep it may be one of the best and complex cars around but it is still a car!! dont be too afraid of doing normal maintenace items:

but shy away from safety critical like brakes steering etc unless you are really confident or is it competent!

 

Great thread! I changed my battery last year, and I noticed no issues. The windows did quit working in the "auto" mode, i.e. the second click where can release the button and the windows continue to the up or down stop. I never considered the window issue to be related to the battery swap. Can't wait to reset them so the auto function works again...thanks guys!

 

Hello All,

Good thread !!!!!
Alternately, buying a battery at AutoZone, or the like and they will install it for you free and recycle your old one, check ahead!!!! Battery in the boot like my STR? They won't change it but will provide the tools for you to do it there including the battery keeper. They are restricted from this because of the battery venting gasses possibly involving the passenger compartment and liabilities associated with it.

Regards,

 

Pep Boys used to run a real good deal on the Bosch AGM battery; if you're not in a hurry you might able to get the 30 or 35 percent off deal. I bought mine last year and ended up swapping it out in the parking lot and just brought the old one back inside for the core refund; I'm pretty sure the installs are free though, I just didn't feel like waiting.
Here is a link to the post concerning the deal:
https://www.jaguarforums.com/forum/x...y-deal-137720/

 

I didn't see it mentioned, but after a battery change, you will need to reset the electric parking brake. Just step on the brake and pull up on the switch.

 

Excellent tips on the reset of the windows and parking brake.
I went with the Bosch Platinum 49-850 AGM battery - its been 2 hours and no issues since :-)

 

Hi,

I've had to pull my battery umpteen times for various reasons. Don't worry about it. The radio codes aren't actually required. There is a 3 button combination you can press that will bypass the radio security code! its easily found on the web. >> + 2 others, i forget which. Even trial and error will get you there.

As for everything else, I have not noticed any other problems with powering down the car for extended periods.

At several points I had to keep the car off the road for repairs for a few weeks at a time. As you now, the battery will run flat in about 2 weeks. So, I got myself a 950CA, (i forget how many mAh, but enough to get me 3 weeks without running the car) monster U-Boat style battery. Total cost £110. Fitting...free aside from my own labour.

Do it man. Don't let them stitch you up.

 

I replaced the battery in my 2004 XJ8 this morning. One issue- one of the hold down bolts was corroded and the swedged in nut just spun in the plastic battery tray. I ended up replacing with a bolt/washer/nut combo. I would suggest using penetrating oil on the bolts/nuts if you have any evidence of corrosion.

 

A year or so ago I had to change the batteries on a Mercedes SLR/McClaren. The owners manual had *such* strong admonitions about DIY replacement that I was afraid of not only destroying the car but also being turned in to the Mercedes Battery Replacement Authority, USA Division, for 50 lashes and a 2 year prison sentence.

I ordered the batteries from the dealer and also spoke with the shop foreman, asking him if there was any possible way I could just do this myself. In a tone that suggested he was sick and tired of answering the same question year after year he said "Have you ever replaced a battery on any other car?"

I replied "yes".

"Did any thing bad happen when you did?"

"No", I replied.

"Good, you're qualified. Just do it!"

I did it. And nothing bad happened


Cheers
DD

 

The buttons are >>|, A.MEM and PTY, and will work on any X350/8, X Type or facelifted S Type with the same infotainment system. It will only work with a radio coded to the same car though, so if you swap the radio over for a different one you will need to enter the 4 digit security code the first time to unlock it.