If the expiry is June 2014, it means that the, pinger in this case, will work for the stated requirement of 30 days. It cannot be shorter than 30 days as that would be non-compliant with the requirement.
The manufacturer provides the life guideline on basis of test results which MUST meet the stated requirements, which stipulates the minimum criteria. Yes, if you have fresh batteries, it will work for longer than that but there are no marks or credit for 'being better'.
Newspapers are not the proper authority on this subject and should never be used as the basis.[/QUOTE]
Not so simple.
They say the batt should work for 30 days. That is based on lab controlled environment.
They also say that actual batt power depends largely on water.temperature, water depth and impact and circumstances of the crash.
Nothing runs according to paper specs.
Like a car that states fuel consumption that is xx km/litre. No car will actually consumes exactly, according to paper specs. Paper specs are tested in a controlled lab environment