Well - we modified the settings on the Victron inverter/charger (that thing with all the superconductors in the last picture) and it seems to have had some positive effect. For the really interested - we found both the charging current and float voltage needed some amendment, and since then we have seen much less high voltage and not the same shocking power drain when high-demand appliances are switched on.
We are still seeing a high drain when we have two or more of our alepnglows on but Pip is about to put new bulbs in all of them and then we'll see. So - some progress and we've learnt a lot about our boat electrics. Still learning even after 7 years!
Sarah went up the mizzen in the morning - and found it was b---y cold once you are 10m up in the air. All the rigging was fine, but it was much too cold to go splashing water about to clean the sail track and other connectors. Which they badly need after sitting in the salty air of Ostia for several months, rain or no rain. So instead of attacking the main mast we faced up to the electrics. And of course by the time we'd finished the wind had died and it was a great day for rigging work.
But instead we opened a bottle of wine to celebrate our successful work on the demon charger.