Did the person that checked the battery health not check the alternator output and give you a printout of the values for this and the CCA values etc

It should be around 14.2 to 14.4V or so with the engine running.

If there was a drain then I wouldn't expect the warning system to flag an issue after running as the battery should, if, it really is healthy and the alternator is working be charged.

Without knowing if the Alternator is functioning correctly it is difficult to diagnose, how old is the battery?

 

No, so far all that's been done is a battery health check (one of the freebies from a chain garage so far from exhaustive, but was the first obvious thing to rule out and free), not a full diagnostic.

Just wondering if there are any other obvious things to check before I book it in for anything more substantial.

Also, I suspect this is not related but in case it's informative, since I've had the car (2 years now), the stop-start has never functioned despite theoretically being "on". I've never bothered to correct this as I prefer it off having read all the issues it can cause, but perhaps there's some sort of link.

As far as I know without delving through the history, the battery has never been changed, so it's as old as the car (about 8 years now). It's an authentic Jaguar one so I assume its the original one the car came with.

If the alternator wasn't working (other than maybe partially), I imagine the car would have failed to start by now as there would be progressively less and less charge?

I'm about to go on holiday for a week, so I'll find out if it goes completely dead over the course of 5 days or so next week.

 

Part of a battery "health check" should include the charging circuit.

Most of the automated testers give a battery voltage reading with engine off and with it running, ie the alternator output.

If this wasn't tested then this is the obvious thing to test next.lAternator diode packs can partly fail leading to reduced output but until you have this tested properly you will not know. This can also, in some cases, cause a battery drain.

The Stop/Start not working does point to a battery that is not being charged at full capacity or unable to be charged to full capacity (the battery management system monitors this and disabled Stop /Start below a certain threshold)

Again, this could be battery or alternator.

Did the person testing it give you any information regarding battery voltage at rest and under load? Any reading of percentage charge and CCA values?

At 8 years old I would be changing the battery, I can be pretty confident that it will be nowhere near its design capacity for CCA etc.

The battery in my car was 9 years old when I noticed it being slower to start followed by a couple of failures to start, it was tested with professional equipment which gave a printed summary of the battery and charging system state which showed it at 35%capacity with reference to the original CCA value

The bad news is that when you replace the battery (or fix whatever problem there is) then your Stop /Start will work again! 🙄

 

If the battery is the original one and now 8 years old I suspect that it is failing, despite the rudimentary health check saying it's healthy. For the price of a new battery, it might be worth just putting in a new one, either yourself or get someone like Halfords to do it, so as to avoid the large diagnostic and then battery replacement charges a dealership will make.

 

I get that problem on a regular basis but I can understand as my XE is now just over 4 years old and I've finally gone over (only just) 8000 miles. So my problem is caused by very low mileage most weeks, so the answer for me is either put the battery on charge or nip off for a 20 mile ride.
Unfortunately my missus has been ill for some time, so whereas we were always out somewhere now she's only in the car when I'm taking her for a hospital appointment.
Not only that but I was in a gigging band and purchased a new expensive amplifier when I ordered this car, one that I knew would fit in the boot ok. The car was delivered a few days before the first covid lockdown and all of our gigs were cancelled and the band finally decided to call it a day. If that hadn't have happened I'd have been up to 2000 or 25000 mile or more by now.

 

Got one of these for my SLK and use it on my XE if it's not driven for a while. Very easy to connect to an XE and leave overnight, or longer.

CTEK MXS 5.0 Battery Charger with Automatic Temperature Compensation, Black : Amazon.co.uk: Automotive

Buy CTEK MXS 5.0 Battery Charger with Automatic Temperature Compensation, Black at Amazon UK. Free delivery on eligible orders.

www.amazon.co.uk

 

Crikey, battery chargers have come a long way since I bought mine 20 years ago!
"Reconditioning mode"

 

Unfortunately not - I don't have any sort of charger myself.

I think for now it's just going to have to wait until I'm back off my holiday and see where we are. I don't actually think there will be a problem with the car starting etc going forward based on the last couple of days, but I could do without the error popping up every 5 minutes when trying to sell 😅

If I was to go and pick one up myself, I've read elsewhere on the forum that as long it is an identical spec, there is no 'coding' to the car needed - is there anything else to be aware of or is it better just to bite the bullet and get one fitted?

There's currently a "gx73-10655-ad" fitted to it (800 CCA, 80Ah) and looks like this might be a bit of a bargain?

S5 A11 Bosch AGM Car Battery 12V 80Ah Type 115 S5A11

S5 A11 Bosch Car S5 Battery - AGM (Absorbent Glass Mat) Bosch Group are one of the leading battery manufacturer companies in the world and have been delivering quality German engineering in the automotive industry for more than 100 years! Bosch is a world renown company name that have and still...

www.tayna.co.uk

 

When I had the battery replaced there was no need for coding and no issues afterwards.

For peace of mind I would be inclined to have the Alternator checked first.

The only time the battery symbol has appeared on any car that I have owned was due to the Alternator either failing or it's drive belt breaking, never with a failing battery 👍

Re a replacement, there should be a type number on the battery, ie S19 or a similar combination which denotes the physical size, terminal type and position.

 

8 year old battery? You've gotten way-y-y more life out of it than it was designed for so you should undoubtedly buy and install a new one to make your related problems go away. Since you are supposedly selling your Cat in a few months, you have to make the decision..

 

I have had these symptoms before, as had my son in his Evoque. Battery change in both cases resolved it.
Stop/start not working is a very good indicator of failing battery

 

I think the old methods are the best. Batteries usually expire slowly and when they start to struggle starting the car, it’s definitely time for a nice new one. You can’t rely on battery testers either. When I bought my 30T it was 2 years old. Serviced by a main dealer the day before I collected it and complete with a battery test certificate. 2 weeks later after a couple of instances of low battery warnings, Jaguar assist (The AA) said it was nackered and changed it under warranty. It was however still starting the car with no issues at all and would have probably gone on for some time before needing replacement. I only called them out because the car was under warranty. I suspect the bar is set quite low for the warnings to appear and is just a be aware indication and nothing to be overly concerned about.

 

Batteries usually expire slowly and when they start to struggle starting the car, it’s definitely time for a nice new one.

My experience with modern batteries is that they sometimes do completely expire overnight, unlike batteries a few years back that gave you warnings by being audibly slower at cranking the engine when starting.
On a previous modern car (not a Jag) I had driven home one evening with everything normal and then next day it wouldn't start and I got the Christmas tree warning lights all over the dashboard. A new battery completely resolved this.

 

Your battery is getting tired. Go for a 90Ah version and also treat yourself to one of the new battery chargers as mentioned (I have the same as pictured). If you only want a cheaper one have a look at Machine Mart page 264 for a new intelligent cherger ron £20 -£40. Ithink the page number i quote is the same as the online catalogue. You can get a good battery rom Halfords fitted and programmed to the car with 5 year warranty. It is very heavy and awkward so worth them messing about with it. The windows and sunroof will need reprogramming (refer to manual or insist they do it. That is not a big job.

 

I wouldn't let anyone at a Halfords near any car I own, ever again!
I had a CV joint boot done on my 407 by Halfords. They then stung me for tracking arm saying they couldn't get it undone to adjust the tracking. When they delivered the car back to me, the heating was on full blast on a hot day and the AC then didn't work. I went back for an AC re charge and they wouldn't do it because of a leak somewhere and quoted £500 + to get the AC working. I went to Kwik-fit and they re charged it for £50 and it lasted all that summer.

Worse the CV boot lasted less than a year. (Wrong or inferior part?)
Got Peugeot dealership to do it this time and it lasted 10 years probably more as it was OK when I sold the car.

 

The standard unit is 80AH and the majority don't need to go and buy chargers.
If the car starts it's nagging message about "saving the battery" just go and give it a decent run.
Regular short journeys can get it coming up but the car will still start fine.

 

My feeling is there is probably more going on than just needing a run.

The car does a good 30 miles a day, with 10 mins or so on the motorway so a full blast, and has done for the last 2 years more or less so something has changed recently. It could be that the battery has just degraded that bit further such that it's setting off the warnings and a good run would charge it more, but I think that would only be a temporary fix/hide the real issue.

I do reasonable miles - I've put about 25k on the car in 2 years so I don't think it's wanting for exercise.

 

Just for info my car has the original battery, is now 8 years old, v.low mileage (18k) and I now only do around 3000 a year. I haven't had any 'low battery' warnings and in June I left it for 2 weeks while on holiday. No problem in starting when I returned and no warnings. Fully functional stop/start too which I do not turn off (unless in slow stop-start traffic). However I do think it's exceptional rather than the norm.

 

I have had this happen with a nearly new battery and so far have not found the cause - see my post in this section. I have found one rather warm relay which I suspect has some connection to the problem.

 

After much investigation I have solved my "Low Battery" warning problem. It was caused by one failing cell in an 80AH AGM TAB (Volta) battery. What was happening was that if the battery was discharged by just a few % the battery terminal voltage would suddenly drop from over 12v to just over 10v. It would stay stable at that and the car could be used but the warning would persist until the battery was recharged. I had to persuade the battery supplier to do a load test on the battery as when the battery was fully charged the standard voltage test showed it to be OK. A discharge test immediately showed up the failure and they replaced the battery under its warranty.

 

Little update - the car started just fine after sitting for a week despite giving me the warning again.

The car is going to the garage tomorrow anyway so I'll get them to do some deeper diagnostics at least.

 

What is the warning you are getting, exactly?

 

It says something along the lines of "Battery low - please start engine" with a red warning triangle and pops up on the little screen between the speedo/rev counter.

 

I know on the XF the BMS will deliberately discharge the battery to go through a self-calibration routine. The procedure can bring up this message and happens every six months. I am not 100% sure with the XE.

 

as mentioned numerous of times already...car needs new battery

 

as mentioned numerous of times already...car needs new battery

Yeah fingers crossed that's all it is.

I know on the XF the BMS will deliberately discharge the battery to go through a self-calibration routine. The procedure can bring up this message and happens every six months. I am not 100% sure with the XE.

I've read about this, but I think it's unlikely given that I've had the car about 2 years now and it's never done it before.

 

Oh God!! And this of course is progress. Oh for nice round ammeter and oil pressure gauges again

 

Oh God!! And this of course is progress. Oh for nice round ammeter and oil pressure gauges again

Absolutely - why do cars have to be SO complicated these days?

 

Because you like options like a heated steering wheel, 825w sound system and electric seats....

 

But these luxuries existed on upmarket cars before the advent of CANBUS systems and multiple control modules for everything, talking to each other over the BUS

 

So you'd be happy if your XE was a few hundred kg heavier due to all the wiring? I think not.

 

My 2015 2.0D is still running the original battery with no issues at 60k; the dreaded stop-start even works...assuming I have forgotten to turn the damn thing off. I give it a regen charge on my cetec every couple of months or so and keep expecting to have problems, but no warning lights as yet. I think I will change it before this winter, though.

 

Some slight developments.

The garage had the car in yesterday, and couldn't find any obvious problems. The battery reported good again for them. To confuse matters more, I've had no warnings for the past 2 days, which is about 4 or 5 stops/starts.

I'm getting them to put a new battery on in any event as I guess it can't hurt, particularly with winter on the way.

Perhaps makes me wonder if it was the BMS calibration afterall.

Another of life's mysteries apparently...

 

Though rare in new batteries, what you experienced does sometimes happen. I'm glad you were able to get it replaced under warranty for free.

 

Whilst I would agree, that I do not use my 2020 Diesel XE for long journeys on a regular (weekly or even 2 weeks basis) I do drive for about 15 miles each way once a week. The engine is running for around an hour in total.

I always disengage the Stop/Start and didn't use the heated seats or steering wheel. On entering the car I got the "Low Battery - Please start your engine" message on the dashboard. No problem enghine started as last week. However when I got home and turned the engine off the message reappeared even after driving for another 30 minutes.

The car displayed the message when I had the test drive but fair enough as it was stood for days at the dealership.
I've checked the alternator belt and it looks OK.

Just wondering just how long the engine needs to run to charge the battery?