On 08/05/2018 12:03, Bob Minchin wrote:
The Natural Philosopher wrote:
On 08/05/18 11:23, Bob Minchin wrote:
Graeme wrote:


I triedÂ* Harry's bulb trick again (small MES panel light bulb between
-ve battery terminal and earth strap), and nothing.Â* Tried using an
ammeter.Â* Nothing.Â* Yet current must be flowing somewhere.

If he has disconnected te battery entirely and put a meter in the
circuit and no current is flowing, then no current is flowing and the
battery cannot be discharging *via any external means*.

So:
Suspect dynamo control box.


Cannot be relevant.

I have a morris 1000 workshop manual somewhere. Send me an email and
I'll try and find the relevant info, scan and send it to you.
Bob

My gut feeling is, that te battery is *intermittently* self discharging
due to old age and crap in the cells.

If its driven about its a toss up as to wehether mechanical vibrations
and shock will leave it in a position where it will self discharge or
not.

As I related earlier, my experience was of a battery that appeared 100%
sound one day, and had done for years,Â* and was dead flat the next day.

Replacing the battery fixed the problem entirely.

My point is that not all batteries fail gracefully.

Bits of broken off **** that short them internally, or leaks between
cells can happen suddenly





Nowhere in the question does the op say
"If he has disconnected te battery entirely and put a meter in the
circuit and no current is flowing, then no current is flowing and the
battery cannot be discharging *via any external means*. "

A heavy discharge meter is your friend (but not your batteries, if it
is on the way out, it may expedite its demise).