Hi Twisted,
As I mentioned the battery was only reading millivolts at the times I mentioned.
In the first case I had charged the battery from new with a modern battery charger capable of up to 16 amps, but then did not ride the bike for about 6 weeks and was surprised that it was so flat. Even the old battery had never gone that flat before.
The charging system on the bike works fine as attested to by the rapid recovery of what appears to be a totally dead battery being able to restart the bike after just a few minutes of use.
I perhaps didnt make it clear that the battery I have currently installed is an SSB Lithium technology. I have never used a battery with this technology before so am not sure what to expect, however I did not expect it to go flat to 0 volts within a matter of weeks. If this had been a lead/acid technology battery I could safely have assumed that it would never recover from such a low voltage, but this Lithium one seems to run just fine once it fires itself up ??.
The run on Sunday was for about 6 hours, so I think the bike should have charged the battery quite well in that time. I checked the voltage this afternoon and it was well over 13 volts, so all good so far. I also checked the battery terminals and noted that they were not as tightly attached as I had thought so maybe that has some bearing on the matter, although the first time this happened I measured the voltage directly on the battery and it was very flat.
I guess time will tell.
Allan