Hi everybody, I am the new kid on the block (or better the new grandpa on the block). Bought the 2001 XK8 2 months ago and found that the battery does seem to go down very quickly, in about 7 days to 11Volt from fully charged. It happens when it is locked outside AND when it is unlocked in the garage. Are there any big users that I should know about or could there be a small earth leakage or is it just a tired battery? How can I find out? Car starts ok but on one occasion, when battery was low, I had the most scary screeching noise whilst the engine turned over and an intermittend knocking once it had started and was running in tick over. Stopped after awhile and hasn't happened again. Love to have some comments as to the problem. Thanks

 

Welcome to the forum gypsywagon,

I've moved your question from Jaguar Forums Feedback & Suggestion Center to XK8/XKR forum. Members here with the same model will be able to help.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

In all likelihood a bad cell but most parts stores (Advance Auto for one) will test your battery for free and even replace it for you if you need to buy a new one. These cars are VERY sensitive to low voltage and bad batteries. The battery should read something in the 12.75v and above with a full charge and bounce back to pretty close to that very soon after you crank the engine. Of course a cold cranking test would tell you just how good or bad the battery is.

 

Don't know about the UK but here in the colonies any auto parts store will do a complete charging/battery system test for free hoping to sell you something. That's where I would start.

 

Welcome Gipsywagon, I agree with RD minor's comments and will ask do you know how old this battery is? it sounds like just an old battery. I see you live in the UK, do you have auto parts stores there that can test your battery?... I'd start there. A good battery will make a lot of difference in how your car functions... more ways than you would think. I would begin with a new, freshly charged battery and go from there. These cars can exhibit symptoms of other problems that can send you looking in other directions when it was a just a bad battery problem all along.

 

Hi and welcome to the forum.


To allow the car to go into electrical "sleep" mode, it should always be locked.
This will minimize electrical drain after a period of, I think, 30 minutes.

 

Quote:
Originally Posted by oyster
To allow the car to go into electrical "sleep" mode, it should always be locked.
This will minimize electrical drain after a period of, I think, 30 minutes.

I didn't know that & as it's always garaged I've been leaving it unlocked & frequently find the voltage has dropped & I have to reset the windows.


To Gypsywagon,
Replace the battery, Europcarparts have a sale on, only £70

 

I left this on another thread last week but here it is again for your convenience(!):-

As oyster says the car goes to sleep after a predetermined time. Any faulty modules/lightswitches can secretly drain your battery behind your back....

If you can get yourself a cheap DVM measure the standing current leaving the battery when the car is at rest - they are (in my car):-

Boot open (light on):- 1 amp @ 0 seconds
Boot closed:- 490mA @ 0 secs, then 400mA @10 secs, 27mA @ 1 min.

All times after ign. off & key out.

Battery will need to be dis and re-connected for this test so refer to the standard reset procedure mentioned elsewhere on the forum.

I have a sneaking suspicion that the old battery problem is due not only to slightly lower voltage, but also that the battery has less decoupling (as it doubles as a giant capacitor) of sproggies on the electrical busses, thereby confusing some of the microprocessors.

 

Hi again.


It should be 60 minutes to power down.

 

Halfords will check the battery for you FOC. Also check that when you take the ignition key out the cover on the barrel closes - they can stick open and if so will prevent the car from going into "sleep" mode. Easily fixed with silicon or WD40 if that's your problem.

 

Thanks for the prompt replies. Will check with the previous owner if he ever replaced the battery during the 7 years he had the car. Also will lock up when in garage and spray ignition lock with WD40. (really thought it would use more power when locked up and security system is armed). Probably need a new battery. Thanks again

 

me id buy a battery 7 years is borrowed time for a battery also id look into a solar powerd battery charger or a trickle charger for when its sitting mine eats up batteries like its a kid in a candy store .

 

+1 on the trickle charger. Saves a lot of headaches if you do not drive daily. Low battery voltage causes all kinds of strange gremlins in these cars...

 

Not to nitpick, but there is a notable difference between "Trickle Charge" and a Battery Maintainer. A trickle charger has a constant current running at a low amperage. A Battery Maintainer is a computerized module that varies the output amperage to meet the needs of the battery. If the battery is 100%, the trickle charger will continue to supply CHARGING amps although the battery doesn't require that much. The Maintainer will drop the charging amperage to a maintenance level that actually doesn't charge the battery, but DOES supply the "sleep" draw to the vehicle, basically turning the charger off.
Both the trickle charger and the battery maintainer will do the job, but the maintainer will be kinder to the battery in the long run. Having either unit installed would be a benefit.
There is another thread in the forum with a lot of information on this, just search CTEK.

 

Thanks batroute, You are right, the cover on the ignition lock does only close half way. I spayed some WD40 into the ignition lock and alternately put the key in and took it out several times. After a while the cover closed about three quarter but couldn't get it to close all the way. Will keep trying perhaps it needs some exercising.

 

I would higly recomend a CTEK Maintainer. My Battery is original, 11 years old and going strong. When you leave the car sit for several days and the battery voltage starts to drop, the electrolite then leaves sulfates on the battery plates, which is unwanted resistance limiting the current the battery can put out. Once you go through few deep discharge cyles like that and sulfates build up the battery becomes useless. It's sounds like you've done two many deep discharges already if your loosing window settings.

When you do replace the battery, definitely buy a CTEK maintainer, it will pay you back in less nuisance resets and false errors, and you won't be buiyng another battery 2 or 3 years later. It will monitor the charge and only puts out short pulses needed to maintain it at full charge.

 

Recently had a similar battery behaviour. Put it on the CTEK in recondition mode.
Maybe the charger will give an error(something like there might be a problem with the battery) , in my case 3 times, but it finally passed the full cycle successfully.
Now the battery holds it charge as it was new.
Best is to remove the battery from the car before doing it.

 

Battery maintainers are one trick ponies.

Most consumer grade battery chargers sold today in the 8-20 amp range also
have a trickle/maintenance/recondition mode available. They are also usually
cheaper and more versatile than the much hyped battery maintainers.

 

This is correct, however maintainers are much smaller, most of the time cheaper, and have (usually) the option to be connected permanently to the vehicle. I find it much easier to casually open the boot, get the short cord just inside the back lip, and connect it to the cord that comes from the actual maintainer, which is mounted to my wall. No fiddling with battery clamps, moving trim pieces, it's just a quick zip-zip and it's done. This also leaves the other actual battery CHARGER available for when you need to to do something else.

 

as my car is a daily driver and is not garraged i find the solar charger works best for me bought mine at walmart for 20 bucks and it has the diode in it so it doesnt reverse drain also a weird side effect if pluged into the lighter socket the raido is operational when using the charger for some reason definately strange .