Car battery problem

Sportsman

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My daughter was driving over to us in the Jaguar XF 3.0L diesel, when the battery warning light came on. From everything I have read, this indicates a charging/alternator fault.
She made it to us and now she has left it here and nicked my Lexus.
As it's a Jaguar I am not sure if it's an actual fault and not just a random Jaguar electrical glitch and don't really want to spend €650 unless I am sure it needs it.
I have had it running for 30 minutes with everything (ac, lights,radio, windscreen wipers) running and no light on.
There is an auto electrician where I can get it tested about 10 miles away, but I am not sure of the range I might have if it fails and don't really fancy being stranded.
Any suggestions? I had a multimeter at one time, but can't find it now. Would it be a good idea to get another?
 

satinet

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Yes it's definitely a good idea to get a multi meter. They are dirt cheap and very handy. You test the TV remote batteries!

If you put the multi meter on the battery when the engine is running you will be able to see if it's getting a charge by the voltage. The daily might be intermittent of course.

You need to set the meter to the correct range. That is probably DC 20v. If you are stuck post a picture of it on here.
 
D

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If you don’t fancy struggling getting to the battery. Eobd code reader, go to live data and that will usually give you the battery voltage, and with the engine running you should be seeing 14.0 -14.4. Switch on all the lights, heated windscreen (front and rear) and see if the voltage drops under load.
 

Godber

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If you don’t fancy struggling getting to the battery. Eobd code reader, go to live data and that will usually give you the battery voltage, and with the engine running you should be seeing 14.0 -14.4. Switch on all the lights, heated windscreen (front and rear) and see if the voltage drops under load.
Not bad for somebody who listens to Britney eh? 👍
 

Neil ofthe nene

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OK, no expert so correct me if I am wrong but once the car is running is the battery not redundant? The question of range does not enter the equation. The battery starts the car as well as keeping the electrics working that stay alive when the engine is not running (alarm, central locking sensor etc.). If it is not charging once the engine is running then eventually it will be flat.
 

Dave

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If the alternator isn't re-charging the battery then the car's electrics are solely dependent upon the battery. Once the battery drops then the electrical circuits will fail
 

carphauler

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There should be a secret menu option, Google it, this will show battery voltage, sometimes hold the odometer trip button down or stalk, start the car still holding the button down after a few seconds it should go into the secret menu where you can scroll through with a press of the button/stalk.
 

Sportsman

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Thanks for the suggestions. Have multimeter on order.
I don't trust Jaguar electronics, it is always showing random warnings for no reason.
 

Foul hooked

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Charging light started coming on intermittently on my XF. It finally failed completely. Be warned, everything stops working. I mean EVERYTHING. Brakes, steering, gearbox the lot. All controlled by electric servos not hydraulic.
The intermittent fault was due to the main pulley coming loose on it’s rubber mounting, which eventually sheared away. £650 bill.
 

Peezartiste

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I have just pex my XF for precisely these type of problems. Having said that the only alarms/warnings I have had has been for tyre pressure low, and one time the interior alarm went off because the phone holder fell off the windscreen. But there are so many accounts/reports of electrical problems in these, I got nervous and decided to get rid. Also due a major service and belt change helped make up my mind.
 

Maesknoll

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Update
The multimeter arrived today. Engine off reading was 11.9v Engine running reading was 14.7v.
So I guess the alternator is OK.

11.9 is low, possibly a battery issue. After you have taken it for a decent run ( or charge battery with a battery charger) let it stand for 10-15 minutes to dissipate the surface charge and check again, you want to see 12.6-12.8v.
 

Sportsman

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11.9 is low, possibly a battery issue. After you have taken it for a decent run ( or charge battery with a battery charger) let it stand for 10-15 minutes to dissipate the surface charge and check again, you want to see 12.6-12.8v.
Yes, battery problems are not uncommon on this model.
 

Pyffy

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At 11.9v the battery seems to be discharged. No amount of running the engine will re-charge a discharged battery unfortunately and will have to be popped onto a suitable charger. You don't mention the age of the vehicle.

For models up to 2015 there are two batteries listed as being fitted to the 3.0 diesel. A standard lead acid or an AGM battery, both are high capacity batteries that will take acouple of days on a charger to raise their potential to be self sufficient if at all. The AGM will need charging on a smart charger so that the battery isn't overcharged and cooked. Once the battery has been recharged it can be succesfully tested without giving false readings as a flat battery cannot be tested correctly. Also be aware that if a new battery is fitted the car will need re-programming so that is it aware that a new battery has been fitted and it's charging system will be reset, failure to do so could result in the vehicle overcharging the new battery and cooking it, thus invalidating any guarantee.

For vehicles from 2015 there is only an AGM battery fitted and the standard battery will be unsuiable as the vehicle charging sytem will overcharge it and invalidate the warrany.

For information here is a free look up tool/catalogue we use at work to sell the correct batteries for customers cars. Any prices listed are soley recommended retail prices and a local motor factor / garage should be able to supply a battery at a competetive rate.

Yuasa battery look up
 

satinet

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Not an expert on this car but 14.7v is normally the charge voltage for AGM batteries which I think are used in stop-start cars.

I used to use lead batteries quite a bit out of cars to power the winches for RC glider flying. You had to use a different charge voltage for AGM. I've got a ctek charger that will charge at 5amps.

Is the battery the correct one for the car? As others have said they can get to the point where they won't charge properly any more, as we all know from winter mornings when the car won't start.
 
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