Dear All, I seem to have set a number of hares running. I am however very grateful for all suggestions even though I am now in "information overload" and approaching that well known state of "analysis-paralysis". Every time I take the dog for a walk around the hill I think that I have got it all sorted out in my mind and then some other consideration arises.
My friend who lives on his boat on the Trent suggested that the first thing to do is to buy a clever battery charging gizmo to be connected between the main engine alternator and the service battery bank which would get more efficient charging out of the engine running time - say £300 and one wire to connect. I haven't yet investigated that but will do soon. However, again, if anyone has experience of that I would be interested to hear from them.
Annie's suggestion that I turn everything off is well taken. I do not yet have paper charts of the Azores because the publisher has run out, probably because someone has organised a race to them ... They are still on order and I am promised that they will arrive.
However, now that I have sailed with a AIS transponder I would be reluctant to turn it off, or in other words it might be the last item to remain on.
The Sea Me is a replacement for the original, traded in with the manufacturer, and now has both X and S band radars. Apparently the S band is used by ships once clear of coastal waters. Clearly it does depend on a watch being kept by shoips, but they do have alarms I think.
I was told the other day by a merchant navy officer that his priority is to watch the AIS and that the radar is now further down the list of priorities.
Thanks again for all the input. Nobody could say that I was uninformed.