Well heard back from the motor factor. The battery supplier took the battery away and charged it on their "Special" charger and reported back there is no fault with the battery. They have provided a print out saying 11.47v and a "good, recharge. The advice was to fit back in the car and go fro a drive to chare it. So after a dinner that's the plan.

While the car is parked its connected to a solar trickle charger into the rear power socket so its nearly always on a charge. If this battery fails and I get another is there really any advantage of the bigger ah rating apart from more cranking power? If the battery is being drained it won't matter how big it is apart from perhaps taking longer to drain.
Anyway this weekend when there's some daylight I'll get a meter on the alternator and battery to see if there is a drain and a charge.

Thanks for all your comments as I appreciate the help solving my problem.

11.47 ??

Yeah .....I know it should be about 12.5v but they say its had a "good recharge". I took it out for a 30 mile drive last nigh and it was fine. I left it on the solar charger and I'll check voltages at the weekend in the daylight

while changing the battery I did notice the offside front had a big carbuncle and split in the side wall, so I'll have to get a new tyre now too.

Batteries don't have a particularly high reading before starting... We often see the reading on the screen when using the IID drop down around 11.1 - 11.2v and still start well!
Don't confuse this with the 13.7 - 14.5v running voltages we are used to seeing when the alternator is working...

Bear in mind the IID voltages, though good, are not quite as accurate as a multimeter on the battery, usually being a fraction lower.  Visiting from DISCO3.CO.UK
Discovery 3 TDV6 Auto HSE Zambezi Silver

well a quick check with a multimeter showed the following
Battery engine off 11.4V
Battery engine idling 12.5V
Battery 2000rpm 14.5V
So it all looks Ok I'll just have to top up the charge more regularly.

Thanks again for all the comments and advise.
Ned

^^^^
I wouldn't say so, I'm afraid. 11.4V for a battery is between 10 and 20% charged which is liable to cause/have caused permanent damage. 12.5V isn't acceptable for an alternator at idle, so I highly suspect you have a failing alternator - voltage shouldn't correlate heavily with RPM.  Visiting from DISCO3.CO.UK
Discovery 3 TDV6 Auto HSE Zambezi Silver

Ned wrote:

Well heard back from the motor factor. The battery supplier took the battery away and charged it on their "Special" charger and reported back there is no fault with the battery. They have provided a print out saying 11.47v and a "good, recharge. The advice was to fit back in the car and go fro a drive to chare it. So after a dinner that's the plan.

While the car is parked its connected to a solar trickle charger into the rear power socket so its nearly always on a charge. If this battery fails and I get another is there really any advantage of the bigger ah rating apart from more cranking power? If the battery is being drained it won't matter how big it is apart from perhaps taking longer to drain.
Anyway this weekend when there's some daylight I'll get a meter on the alternator and battery to see if there is a drain and a charge.

Thanks for all your comments as I appreciate the help solving my problem.

Sounds like our 2007 TDV8... shortly before the alternator failed at 63k