After reading the report on PLB it has come to my attention that the McMurdo PLB plus has a replaceble battery pack. The picture on the report shows what apperars to be simply seven AA lithium batteries connected in series. This picture can be found on page 84 of the second report or appendix 3

Is this true?
Is it possible to carry AA batteries as a backup battery pack for the PLB?

McMurdo sells a user replacement battery for about 90 usd.

I will be purchasing my first PLB within the next two weeks so any ideas you have will be welcome.

Does a PLB or Epirb only work in the US, or also in Europe?

Most proprietary battery packs for electronic gear (except really small stuff like cell phones, for example) are comprised of standard size battery cells (AA, AAA, AAAA, and others) permanently wired together. If you break into the pack you'd see that. When you take your rechargeable pack to be serviced at the many such vendors out there, they cut open the pack and replace the cells, then glue or re-weld the pack together. All that being said, the cells used in PLBs are not your ordinary lithium cells and, no, you cannot use standard AA-lithium cells, for a variety of reasons, besides being illegal. Trust me on this. <~> Quite frankly, there's not much reason to carry a spare battery pack anyway. The 24-hour minimum operating life (at -20°C (-4ºF) of a PLB is more than adequate to get you rescued in almost any PLB appropriate survival circumstance.

406 MHz PLB0s, EPIRBs and ELTs work anywhere on our planet. For more information, see:

http://www.equipped.org/faq_plb/default.asp

there is a reason why they are sold here too...
A source for these things:

PLB:
http://www.bever.nl/asp/actueel/productnieuws/2006/2006_noodbaken.asp

EPRIB:
http://www.countrystore.nl/main.php?id=UNIFACT_51df5398bd24b16d26a32b3395523664

Other sources are martime store's or contact your local KNRM station for local sources.