js.b1 wrote:

Second, will the panel be enough in overcast winter?
30mA sounds little but over 24hrs totals 8.64 watt at 12V.
You can't express it like that. Do you mean 8.64 watts for an hour? If
so it doesn't sound as if it would be difficult for the panel to at
least help the situation significantly.

As I said in a previous post I used one of these for years and it kept
the battery in good nick right through the winter. Although it was
physically big; could have been 20W I suppose. It failed eventually; a
bad contact that I couldn't resolder.

Bill