It's a Magic Mouse II and has been working fine for the last 3 weeks since I became the proud owner of a Mac (runs El Capitan 10.11.4).
It has been in fairly intensive use during this time as I have been re-loading all my Windows documents and slowly making changes in the most used so that I can bin the .docx and continue with .pages. I see no point in keeping files in two different formats so my farewell from Microsoft is giving me a push to cleaning out and editing my documents.
Today I made a start on all the copy/pasted information I have listed on a second-hand forum. I had unfortunately 'lost' all my original files and photo's when Windows badly let me down on my Dell desktop. To save myself the enormous trouble and work of reinventing the wheel and making new photo's and description for hundreds of individual items, I decided to copy/paste what was still listed so that I only have about 25 or so to 're-do'.
This then gave me the chance of some intense editing (bold highlights, cleaning up spelling mistakes which Word had missed, changing the layout of the descriptions etc etc). So yes - the mouse was in fairly intensive use today but still shows 35% of power left. It will eventually require the power cable to reload fully as it doesn't use regular batteries.
So I will just have to live with it disconnecting from time to time which is a bit of a pain when trying to complete a particular task. But my female logic still questions why it scrolled fine in each and every Internet site I visited as well as in various Numbers documents but refused to work in Pages.
Perhaps I should put this question to Apple and see what they come up with for an answer.
And if it becomes too regular, then I'll buy a corded mouse and be done with it!!
Thanks again for this answer though.... the fog has slightly cleared (*_*)