Although my memory is a little vague, and it won't apply to your
situation given the hardware you are using, for a couple of years I took
my music with me via Squeezeboxen when on vacation in the tropics.
Difference is I used a laptop I was taking with me anyway and a Boom.
I used an -ad hoc-
I continued using Controllers long after others had migrated to mobile
apps (what I do now). On multiple occasions I had to replace batteries
after symptoms just like those described. I still have a spare.
You can easily find replacements fairly cheaply on Amazon (e.g.
