I have a conversation today with ACR. I understand their position on why they want to service their products. In addition to changing the batteries the unit is then tested for water entry and checked to ensure it complies with the Cospas-Sarsat certification the unit was issued when submit for certification. Plus another way to look at the cost of a $130 (or so) battery replacement is that the unit is good to go for another five years which comes out to $26.00. Also if the PLB is activated for an emergency ACR will replace the batteries for free or provide a brand new unit.

I would like to state that I do not recommend anyone to do their own battery build to service a PLB.