I hate to resort to open questions without searching every posted possibility to solve my issue, but my eyesight has been failing and I can't read through all the hundreds of posts. I only have a couple of questions that will seem elementary, but I'm stuck for a simple answer.

1- last time I drove my Xk8 I wound my way home through some nice "S" curves, both uphill and downhill. I shifted down and up depending on the grade and speed. Common stuff, I thought. But part way home my trans seemed to stick in 2nd or 3rd gear. I'm not sure this is "limp mode", but all the way home it would not shift out of that gear....hard on starting from a stop. I thought "limp mode" kept the trans from shifting up from first so you can't go more than 30-40 mph. This is different.

Second issue, maybe related to the first: after several non-starts I gave up and replaced my Maxx H8 battery. Fine, but before I hook it up I am using a 2A trickle charger to make sure it is FULLY charged from its long rest on the store shelf. No problem, but it seems to be taking a LONG time. But the next question has to do with the actual circuitry and resetting everything:

SHOULD I DO A HARD GROUND TO DRAIN ALL THE RESIDUAL GREMLINS BEFORE I CONNECT THE NEW BATTERY????

 

Aside from needing to reset the window memory, I don’t know of any reason not to do a hard reset. It only takes a minute and costs zero

Z

 

If your battery has been on the shelf over 6 months forget it ....slow to charge means its sulphated and you will not get it back (maybe) unless you use a modern pulse charger which will take it up to 15v and then hold at 13.8 .
You need a float charger on it 24/7 when you dont drive it for a couple of days.
Remember the alternator will not fully re charge a run down battery on the car . Its 120A output is to supply loads like air con/wipers HRW and the best it can do for the battery is about 15A.

 

Thank you! You guys are the best.


Any thoughts on the tranny not shifting? Will it correct itself after I get the battery hooked up?

 

Has the gearbox been serviced, or at least had the fluid level checked?

 

The tranny was replaced at about 82,000 miles before I bought the car in 2008. 117,000 - 82,000 = 35,000. Very few miles driven in the past 5 or more years. No servicing or fluid leaks or problems....except what I would have called a "limp mode" experience after hard acceleration onto the local freeway a few years ago. I guess that's identified by a stifling of upshifting into the higher gears....and then not wanting to restart after I got gas at a local station. I almost called a tow truck, but then it miraculously started again after an hour or so. Hmmmm...that said, when I went on this last drive I stopped at the local cemetery to visit some family graves....tried to restart the car and...nothing. SO, I disconnected and reconnected the battery and it started, but the rest of the way home it seemed to be stuck in 2nd or 3rd gear. Moving the shifter made no difference. I have not driven it since, replaced the battery, not hooked it up yet, so I don't actually know if there's still a problem.

I have tested + for Covid (again) so I haven't had the strength to get out there and take care of it yet.

 

Me and my wife has three cars that are stored 5-6 months every year with the battery disconnected, Charges them every spring and they have always been good to go.
And I do not believe that every single battery at the battery store are newer than 6 months from factory.
Of course it can happen that batteries, as any thing else, is DOA but to forget every battery that sits for 6 months would be very expensive.

 

this may be the norm with your other cars, that may or may not be newer than the XK and / or with a more robust electrical system.

The older Jaguars are a cat with different spots.

At the age they are now at, they do require supplemental charging. The wires and associated circuitry are twice is old as they were designed to last. At this point electrical resistance to current flow is not speculation, it’s the reality of ownership.

You may not want to treat the XK differently than the other cars you own. Your call. But along with that assessment comes at the inevitable risk of not being able to enjoy the XK to the fullest possible degree.

to wit, a battery tender does work wonders for all kinds of electrical gremlins.

just my opinion and observation.


Z

 

How long you can store a battery depends on the type of its construction and how sulphated it was when stored..In the trade we would say 100 days to discharge and 100 days to turn to scrap.
It depends on the temperature ,Norway ? You can stick a battery in the freezer at -18 and thaw it out in the spring and it will still be 100% charged.
What do they do with the batteries on Plant in Alaska in the winter? Charge them up and let them freeze Fully charged battery electrolyte goes to gel and does not expand to crack the case.

 

I think you are correct that these cars, their batteries, and their circuitry need constant attention. Normally, my jag would be in the garage where I just hook the 2A trickle charger to the battery. It's outside right now, but I can still do that for short periods. My issues is with leaving the trunk lid askew or open for the power cord(s). I usually stick a rag in the latch and lower the lid until it barely rests on the cord, but I am suspicious that either turns on the trunk lights OR alerts the security system that the trunk is "open". I can pull the bulbs, but that still leaves the security system. If I cannot latch the trunk, how do I charge the battery without having the car's system constantly draining amps from the battery???? I don't think I want to disconnect the battery and then have to hook it up just to start or drive it.

 

I asked the same question when I bought my XKR six years ago.


the old timers here assured me that the trunk seal was thick and wide enough to close on the thin charger cord without any damage or unintended consequences. They were right. With the truck closed on the charger cord I can still move it in and out of the trunk very easily. After hundreds of trunk openings and closings, the trunk seal still looks to be in “as new” condition.”

 

I dont like feeding the 12v down a long thin cable due to potential voltage drop..I have the charger in the trunk and use a thin ,about 8mm mains cable (from a vacuum cleaner) in through the seal. This cable feeds two floating outlets ,one for the charger in the trunk and one behind the drivers seat for the dehumidifier in winter.

 

The trunk lights will time out after a few minutes with the lid unlatched, and my car does go into some depth of its sleep mode as the front (LED) side lamps & markers extinguish. That is also the case if I leave it unlocked.
The CTEK has no issue with maintaining the battery, provided some eejut doesn't leave it disconnected...

 

Thanks. That's reassuring.

 

All makes sense. Now I can go put the bulbs back in.