There is an alternative. Go to Systems preferences > Magic mouse ... and as long as it shows as connected you should get a charge level there.
It's all very well to show an element of impatience but there is four month gap between this post and the original one, whatever the reason. And you aren't the original questioner.
Why not raise a new thread, set out your problem, what you have done to find a resolution ... and we'll take a look at it. As things are we don't know what machine you are using, what OS you are running, what version of mouse you are using.