S-Type - sudden battery death syndrome

[simpo two]

I got a 3.0 SE 2001 a couple of months ago and everything works fine.
But - one morning two weeks ago the remote failed to unlock it. On investigation the car battery had died in the night, reading about 7V.
It looked like the original Jaguar battery, fair enough, so I got a Halfords equivalent, installed it and it worked fine.
Until this morning. Stone dead and reading 4V.
I used the car last night to get a takeaway and it was in perfect working order, no hint of a dying battery.
Is this a known problem on this model?

Recharging is a pain as unlike my old BMW, you have to disconnect the battery first - so all dash settings and radio code are lost... they seem to have addded lots of frills and forgotten the basics.

All ideas welcome please!

[GavinPearson]

Quiescent battery drain is an issue on these cars and can be caused by a module not shutting power consuming devices down.

Main dealer job.

[simpo two]

GavinPearson said:

Quiescent battery drain is an issue on these cars and can be caused by a module not shutting power consuming devices down. Main dealer job.

Thanks Gavin. If it was gradual battery drain (like the TVR) I would expect starting to become harder day by day as the battery grew weaker. By contrast this seems to be occasional and total.

Would logic dictate that it's a circuit not switched through the ignition, like cig lighter, mobile phone? Whatever it was killed the battery stone dead overnight.

The only thing I remeber doing out of the ordinary before it failed last time was switching the headlight control from Auto to Sidelight (whilst parked for a few minutes) then back to Auto again. However there were no lights on when I left the car overnight...

[triple7]

Hi Simpo, saw your plight. This happened to me on my Range Rover, turned out to be because of motion detectors using same freq as key fob and the car energising, something to consider maybe, see here,

www.pistonheads.co.uk/gassing/topic.asp?t=147521&f=91&h=0

G

[simpo two]

Thanks 777, that's spooky!

The car is about 25 feet from next door's PIR light, at an angle of 160 degrees - probably out of harms way. But it's a thought.

So the car could quietly energise itself, with no exterior sign of anything wrong, no flashing hazards etc... bizarre!

[triple7]

Yes, it was the alarm system. Although the doors don't unlock or anything, the car's brain is active in anticipation of you starting it up, even though you haven't physically pressed the key fob, the car just thinks you have.

Check it out with an ammeter off the battery to see if the car is still drawing power when shut down. Then start pulling fuses to stop the drain if that is the case?

G

[John Millar]

Service buletin S414-01 describes Quiescent current drain specifications and test procedure, although not diagnosis or remedy.

Extracts from S414-01

" The four switched power relays in the rear distribution box will stay active until the last SCP message is sent. This process will last up to 30-40 minutes"

Then follows a list of items to record for when battery is disconnected, radio codes etc.

TEST PROCEDURE
1/Disconnect battery neg.cable, test voltage,if below 12.5v recharge. Refit Batt Neg cable

2/Turn ignition sw.to pos.II and leave for 30 sec.
turn off and remove key.

3/ensure radio, interior lights, phone are switched off. also that exterior lights are in off pos. not auto.

4/Close all doors and bonnet, with the boot open, move the latch to the closed position. Disconnect the boot lights.

5/Disconnect bat. neg. cable. Connect DVOM (AMMETER) between the neg cable and the bat. neg post to perform the test.
Measure current drain

The expected readings are as follows:
Times given are measured from when last door was closed.

Initial drain- 4 Amps and above
up to 2.5 minutes-3 Amps and above
2.5 to 7.5 minutes- up to 2.5 Amps
7.5 to 30 minutes- up to 2 Amps
30 to 40 minutes- up to 0.8 Amps
40 minutes plus-0.030 Amps (30mA)

After 45 minutes the drain should be no more than 30mA

______________________________________________________
I have a paper copy if you need it.
Rgds
John




>> Edited by John Millar on Friday 14th January 23:07

[simpo two]

John,
Many thanks for that comprehensive answer. Having a car using so much curent doing nothing is asking from trouble I think. I don't see whay computers need 40 minutes and 4 amps for a post-journey chat...?

[John Millar]

G,
It sounds excessive I know, but it will only take a small percentage of battery power reserve from a healthy battery. I have heard on the XJ or XK it was related to faulty O2 sensor systems.
John

[hungryjim]

this could be one of a few things.

The car needs to have a regular amount of lengthy journeys in order to recharge its battery. If the car constantly starts and stops then eventually the battery will enough charge to start.

Also check that the phone is not drawing power from the battery ie. switch the phone off and see if this solves the problem

If anything is tampering with the cars security systems then the immobiliser will be activated which draws alot of power from the s-types battery.

Only other thing i can suggest is leave it on a trickle charger overnight, it will reduce the life of your battery but at least the car will always start.

[simpo two]

hungryjim said:

this could be one of a few things. The car needs to have a regular amount of lengthy journeys in order to recharge its battery. If the car constantly starts and stops then eventually the battery will enough charge to start. Also check that the phone is not drawing power from the battery ie. switch the phone off and see if this solves the problem If anything is tampering with the cars security systems then the immobiliser will be activated which draws alot of power from the s-types battery. Only other thing i can suggest is leave it on a trickle charger overnight, it will reduce the life of your battery but at least the car will always start.

Hi,
Car doesn't often do long journeys, but then every other car I've had (see list) has been able to cope with the regime!
Phone is not present, only the rig for one. Could this draw power anyway? Should I get a tecchie to cut a wire?
I don't mind using a battery conditioner for the Griffith but I didn't expect to have to nanny a Jaguar!

[GavinPearson]

You should not have to trickle charge the Jag, it's a genuine issue covered by a TSB.

[gchandler]

Hi Simpo

My Jag seems to have parallel problems to yours first the warning light and NOW my battery has gone dead, (I was just about to go out and buy a replacement). Did you find out what caused the problem? I dont use mine much its been about two weeks since I last started it.

Graham

ps the warning light went out as you said, has yours stayed off?

[simpo two]

gchandler said:

Hi Simpo

My Jag seems to have parallel problems to yours first the warning light and NOW my battery has gone dead, (I was just about to go out and buy a replacement). Did you find out what caused the problem? I dont use mine much its been about two weeks since I last started it.

Graham

ps the warning light went out as you said, has yours stayed off?

The warning light issue seems to have been seperate - it cleared up fairly quickly but the battery still expires at random intervals between 24 hours and three months. It seems to be worse in wet weather. Coincidentally it's going into an indy next week to be 'looked at' - we think there might be an issue with the electrics in the boot, humidity etc.

[gchandler]

Thanks for the reply

A pal of mine is going to lend me an "optimate" I will let you know the outcome

[simpo two]

gchandler said:

A pal of mine is going to lend me an "optimate" I will let you know the outcome

Good luck! I have a similar device for the TVR and it works well. However since my Jag can eat an entire fully charged battery to 0V in 5 hours, no charger is going to keep up

[cardigankid]

Aargh!!!

[simpo two]

simpo two said:

However since my Jag can eat an entire fully charged battery to 0V in 5 hours, no charger is going to keep up

This car is jinxed - not only two cracked windscreens in less than a year, but this evening I was scudding home up the A12 at 80 when there was a big 'bump' as I crossed the line of catseyes followed by a nasty vibration - and after 10 minutes in a lay-by with the aroma of very hot rubber, came home on a spacesaver... scary moment when I didn't think the wheelnuts were long enough to tighten up (it has 18" BBS Monacos) but they worked, phew! So that's another thing for Mr Jagman to fix tomorrow!

[.richard]

Had similar problem on x300 when under warranty. Turned out to be relay for cooling fans switching on even when cold(according to dealer). No further problems seven years later.

[simpo two]

.richard said:

Had similar problem on x300 when under warranty. Turned out to be relay for cooling fans switching on even when cold(according to dealer).

But you'd hear the fans running after you switched off... And if they weren't running, they wouldn't be drawing current - would they?