Phonak charge box, Which side is the positive and negative pole?

I think it likely the connections pass 5v from usb. That would be dc, and polarity usually matters when you’re talking dc electricity. If you were trying to come up with a way to charge an ha other than the charging case, then it might matter. Quick determination via multimeter is correct.

WH

Yes, I know multimeter can give me answer and I even took picture with multimeter before left home. But I don’t know why the picture disappears,maybe I deleted it by mistake…

P,M series,actually I believe all phonak/unitron which can be put in such box hole are the same .
If it is hard to put both two multimeter poles into one home, you can put one pole in left hole left pin and put the other pole in the right hole right pin.
thanks in advance.

Looking at the case open with the top hinged away from you, the pins on the left are hot and the right are ground. 5vdc to like 4 digits exact with fluke dmm with case running off the battery pack.

WH

left plus, right ground.
left and right same as marked on the picture I posted,right?

Glad you are back in business!

WH