I'm traveling over the holidays so my XK8 will be sitting in a car port in Houston, not sure how cold it will get.

My battery has been showing signs of age recently - occasional warning lights and codes flashing up then disappearing. Needle on battery gauge is just below half without engine running.

So should I just leave the car and order a new battery for when I'm back. Or disconnect the battery - would that keep it alive? I could possibly get a trickle charger but that battery would have to come out of the car then any way to plug it in....

 

Do you have other options ?

I would be looking for a place to park the car where I could have it hooked up to a batter tender while sitting idle


Z

 

If you can't use a battery tender remove the battery and charge it before you put it back in. Three weeks sitting with a weak battery probably means no start.

 

With all the postings here of the value and perhaps necessity of keeping the car on a battery tender, it makes one wonder why every car is not already taking advantage of a battery tenders benefits.

It’s hands down the easiest maintenance regimen I’ve ever encountered.


Z

 

Agree, we go south for the winter months and the battery tender keeps the battery fully charged and ready for when we get home again. Greatest thing since sliced bread!

 

Why not just go buy a new Battery and a Battery Tender... Hook it all up before you leave....Then when you return all you would have to do is get in it and start it up.............or does that make too much sense?

What is going on here?

Billy Clyde @ Cinco Ranch

 

Haha good point... I'm kind of resigned to buying a new battery soon so why not just let this one die while I'm away and order a fresh one to arrive before I return? My car port doesn't really lend itself to leaving electrical things plugged in...

 

I assumed a tender was not an option. But I think it would be better to disconnect the old battery, or even remove it.

 

Yeah that sounds like the best plan thanks..!

 

Only do not forget one important thing. And seriously hope you are not living in the State of California or any State that requires you to have a Smog test every now and then or so!
Coz disconnecting battery or even if you use a OBD II scanner and erase the codes, throw one nasty hard to remove, new code, called P1000 that is not an indication of any real error but this code alone will lead to your instant failure of emotion test and Smog exam!!! The funny part, getting rid of the code is really really hard, even the dealership may not know how!

So be aware of this also when my battery gets disconnected, I sometimes get unusual car behaviors later on and down the road, including a security lock where two red lights appear in-dash and nothing electrical works!

I say do nothing only buy a jumper pack s.a. you get in Costco for under $100 and in HarborFright for about $60 and have that ready for when you come back. The car may survive especially if you have no existing parasitic battery drainage.

Another alternative that appears logical but I don't have enough personal experience with is to have a Solar pannel Tenderizer installed, as long as you are not garaging indoor or living in a state where the sun is shy!

Best of luck.

 

Bring the battery with you to the UK and I will charge it up for you when you come to look at my XK8 ..You can take it back fully charged and tested. yea right.
I think you need to put the effort in to get power into your carport . they do make long cables you know . Hole in the house wall and cable across under the roof to a pilar. I will show you how to mod a charger to give you a 13,5v output when you get here.
for me if no power then buy a new battery .keep it in the house and just fit it when you get back.
See you soon.

 

Buy a solar cell trickle charger. I fitted one permanently on the back of the back seat of my convertible. Cheap as chips.

 

Yes I tried that .. a 5w panel was useless but you could be in blazing sun 8 hrs a day but then of course you would have to leave the car in the sun do not so clever

 

This is the most logical solution for a really old car.
The problem: Most, if not all the new cars are dependent on numerous internal small computer units and electronics that even in park state, they need to be active and keep the car in the norm. XK8 for being introduced in the later 90s, was a very well advanced and ahead of its time, car (So many computer-controlled features and self-regulating electric components) That is why you do have a small continuous discharge in all cars, when parked for long, able to deplete a good battery, if given enough time, especially in cooler temperatures. That is why you should not disconnect your battery fully or be ready to re-calibrate a lot of functions, some may need the dealer's involvement with the dealer's grade, a very expensive scanner module, or a hefty charge from the dealership! (Ah those ole good days where life was simple and understandable!).

So let me ask you as I do need this too:
Have you done this on your own XK8? and if so what was the longest time you disconnected the battery and did you have any problems when putting it together (Except that notorious P1000 that I described but is probably of no importance to you or anyone in a territory where annual smog test is not an issue).

Thanks in anticipation for your valuable experience,/reply.

Wow... And I was told the smarter Europeans have ways to "Rejuvenate" and "Re-use" the old batteries, essentially never allowing an acid battery to die!!! And though I have never done it, have heard about the removal of acid, treatment of the chambers with Bicarbonate solution, then refill, replacing sulphuric acid with "Epsom salt solution"!!!
So you say all are wrong?! 🤓😜😁

 

So I left in a hurry and didn't connect the battery but I'm feeling better about that now...! I might ask a friend to pop in an fire her up a few times while I'm away and order a fresh battery
for my return.
I did have a P1111 code on the car the last time I checked but I assumed it was because I have quite a cheap OBD2 scanner... it also seemed to set off a P1797 (I think) code with along with performance restriction and transmission fault message AND low oil pressure warning... again I'm hoping this is a battery symptom as the car had been undriven for a few days!