Disco 2 Battery draining in minutes!

Hi All
Dont think Ive posted a question before, so here goes!
Well I said the D2 (Ive never named my cars, but D2 sounds ok, missing R2 part though!) was rewarding me for all the recent work by killing its battery, but I jumped, too soon, into buying a new one.

New battery fitted yesterday, drove the car for 1 mile, then thought, lets check if shes charging, left engine running, checked voltage, 10.5 V !!!!!!!! and dropping very rapidly, increased revs made no difference.

After another minute, usual array of (false) warning lights, low voltage, then stopped engine.
Battery finally 9V!!! Exactly what happened to the original battery.

Im going to get out to her shortly but first thoughts:
How can a battery with a decent Ah rating, 110Ah, discharge so rapidly without any "signs"? No smells/smoke.
Even without charging, normal use, just headlights on, would not run it down so quickly.
Why couldn't the Alternator "keep up"?
It didn't discharge more over night, its still connected.

What ive found online so far relates to charging issues.

It "could" be: "ABS valves energised" taking lots of current
Glow plugs still energised?
The winch somehow taking a huge load? Doubtful, the control unit wasn't plugged in.

Any thoughts, suggestions gratefully received.
Thanks Mark

The alternator is knackered if you're seeing voltage that low with the engine running....

Hi Bennehboy
Thats my feeling but I cant see how the battery can go flat so quickly, unless the alternator its self is draining the battery somehow?
Ill get togged up in a min and have look, my Fluke wont measure current at the min so im digging out another multi-meter.
Mark

If the output from the alternator is duff it can actually damage your battery...

Either fit a replacement alternator, or refurb it, regulators, brushes, and rectifiers can be bought on ebay easily enough

Ill check the wiring then unplug the Alt and check the outputs direct from it.
Its didnt get that wet at Yarwell last week, maybe its just "its time"!
Ta Mark

Found what I hope is the problem!
When I took the engine out in April the stud to attach the output cable from the Alternator looked like this:

Now it looks like this. Not easy to see but basically the cable has somehow come off the stud and the arcing has chopped off the stud above the nut!
Very strange!
I will make up an extension piece so I can re-attach the cable, fingers crossed the Alternator is ok!

Well that'd do it lol

Thats the "nice" thing about having a Landie, its always coming up with new ways of making life "interesting"!
Shame I broke my own rule and bought a new battery instead of looking for the simple solution first!
Mark