I seem to have an issue with my 59 plate TDV8.

Had it around 6 months. The battery always seemed to sit at around 12.3v after resting for a while, often though it would drop to 12.2v and this would set the tracker unit mad, sending me low battery warnings all the time. So, after some checks, I changed the battery.

The new battery was better, but not much. It tended to sit at around 12.4v after a run, and the alternator seemed to be kicking out around 13.8v. Never any more. So, again, this was changed.

So, new battery and new alternator. However, the battery still doesn't seem to hold much charge. again, it'll sit at around 12.4v, sometimes it'll rise to 12.8v, but not very often. The length of run doesn't really seem to matter.

After a run of around 80 miles today, we were sat waiting for my wife and my son turned on the TV. It lasted all of 5 minutes til it all turned off with a "low battery" warning.

I've also found that it rarely has enough power in the mornings to run the pre heater. Sometimes it will, mostly it'll run for 5 to 10 minutes before it shuts down because of a low battery.

It doesn't seem to be related to a "drain", as it shows at 12.4v even after a long run.

What have I done wrong?

My understanding is that the alternator should be kicking out just over 14v and that 13.8 is really just enough to be charging the battery, and it'll be slow to do it...am I right? What else should I be looking to change?

Thanks for any advice.

HNY!
I’m no mechanic, but would I be right in thinking you may have an earthing problem? My car has a new battery and alternator changed three years ago! Start up reads 12+v then within seconds, goes to 14.3v
The boys who know will be along real soon  2014 vogue se

I’m no mechanic either but I would say you are along the right lines if the alternator isn’t putting out enough charge, should be 14.2 v +, but I think I have read somewhere that some alternator output is controlled via an ECU based on demand. One way I tested an alternator recently to check for low output was to take the positive connection directly from the alternator or the battery if not accessible and the earth from the alternator casing to try and rule out a bad earth - whether that is ok on a Range Rover being a fussy little princess I’m not sure.
You could check inside your terminals are clean or use some scotchbrite or emery
I have heard of connecting a jump lead from the negative terminal to the engine as well to check for bad earth

You have a drain somewhere, which may only be present when the alternator is charging. Should see 14.2v

What voltage is at back of alt to chassis earth, compared with +ve batt terminal engine running to earth, and +ve batt terminal engine running to negative terminal? Cheers

James

If you have a new alternator and new battery and still only get a battery voltage around 12.4 V it suggests to me you have a poor connection somewhere on the charge circuit. After a run of 80 miles I would initially expect a battery voltage of about 12.8V. If you have a battery voltage of 12.4V and go for a run I would expect a charge voltage of about 14.8V for a period slowly reducing to about 14.4V or so as the battery charges.
I would initially check all cable connections for condition and tightness.
If you can it would be worth checking the resistance between the battery -ve terminal and the engine block, it should be zero.
It's not inconceivable you have a broken / damaged cable that is not obvious ie within the insulation.

I believe the later emissions controlled vehicles (5 & 6) only charge to 80% battery capacity to allow for regenerative charging capacity.
As only 50% of the rated Ampere Hour capacity of a car battery is usable anyway, we have to make do with just 30%.
So a 100AH battery only has 30AH of usable energy.
My L322 will only give a few minutes of Audio before getting the 'low battery' warning.

No such problems with my '72 Classic (TV / Radio ? - what are they ?) Forty years of progress. 1972-2012

+1 for Arbuckles description. My 2011 VSE can do a 400 kilometre trip and if i open the doors 5-10 times is will say low battery. I can drive 30 kilometres and watch dvds for 1/2 hour with no issue. I used my IID TOOL to moniter the live values for battery charging and battery level percentages wise. If the low battery warning comes up , the live values ahow 77% ish battery and charging is at 14.8. If no low battery warning then IID tool shows 82% and charging at 12.8 ish unless decelerating when it will increase to 13.8ish. 2015 4.4 AB
GSXR 1000 K5
R1 1998

Thanks Dolph34 for the figures.
Compliance with Euro5/6 has greater implications than just emission control.
Motor homers and those towing a caravan will find their auxiliary battery and fridge do not work as expected with conventional wiring. Forty years of progress. 1972-2012

No problem Arbuckle , i was all for changing the altenator until i saw the live values and other members shared their experiances. I would imagine a larger battery would help. I have a 105 ampere, 950 cca currently ( sic) may look for more powerful one next time. 2015 4.4 AB
GSXR 1000 K5
R1 1998

the more i read about these kind of issues , the more inclined i am to stick with my 07 3.6. It just ludicrous.
Sounds like the OP has spent money on a problem that is designed. WtF.

BTW, Infiltrator, are you aware you need to tell the car it has a new battery. It does effect the way it charges. 2007 Vogue TDV8 in Zermatt Silver with Charcoal

If it hadn't been for mileage i would have stuck with my 3.6 Grofus. Fantastic machine. The charging ' issue ' on later models is a bit bizzare. Even with the low battery warning the RR never fails to start or even turns over slower, i think Arbuckles description nailed it. 2015 4.4 AB
GSXR 1000 K5
R1 1998

Maybe the solution is to fit an auxiliary battery.
And yes, a sorted 3.6 is superb.  2007 Vogue TDV8 in Zermatt Silver with Charcoal

Thanks for all the replies. I've been driving LR's for the last twenty odd years, and the thing I love is that there is always help out there.

Thanks again.

Grofus wrote:

the more i read about these kind of issues , the more inclined i am to stick with my 07 3.6. It just ludicrous.
Sounds like the OP has spent money on a problem that is designed. WtF.

BTW, Infiltrator, are you aware you need to tell the car it has a new battery. It does effect the way it charges.

nicedayforit wrote:

If you have a new alternator and new battery and still only get a battery voltage around 12.4 V it suggests to me you have a poor connection somewhere on the charge circuit. After a run of 80 miles I would initially expect a battery voltage of about 12.8V. If you have a battery voltage of 12.4V and go for a run I would expect a charge voltage of about 14.8V for a period slowly reducing to about 14.4V or so as the battery charges.
I would initially check all cable connections for condition and tightness.
If you can it would be worth checking the resistance between the battery -ve terminal and the engine block, it should be zero.
It's not inconceivable you have a broken / damaged cable that is not obvious ie within the insulation.