John,

I had the same question a few months back. I was also informed that the battery can only be changed ONCE. After that the unit is dead as far as they are concerned.

AND, I could get 1.5 of the PLBs for about the same price! Some of the replies I got talked about the time it takes to activate a PLB. OR, the automatic activation.

What I decided was to NOT put a new battery in the old unit. By going the PLB route I;
1. Have redundancy. I have 2 units, 1 for Jill and 1 for me. We can set them off 1 at a time and double the time, OR if one does not work we have a back up.
2. We can each carry one with our harness. MUCH easier to take with us.
3. Once in the raft, we have plenty of time to activate the unit! Speed is NOT a critical issue.
4. If I am NOT able to activate the unit, I DO NOT want some one to risk life and limb to find my body!

Just my ideas.

Greg