AF447 emergency locator beacon battery

[chx21pop]

I've been following the AF447 thread up above in rumors and news and someone mentioned that the flight data recorder was made by 'Benthos'.

If correct according to the link below the beacon's operating life could have
been at least 90 days with the optional battery.

..............................................
http://www.benthos.com/pdf/362drevk.pdf

Operating Life:
≥ 30 days with standard lithium battery
≥ 90 days with optional lithium battery
............................................................ ......

Can anyone comment? Is the optional battery ever installed/why/why not etc.?

Thanks