Thats an intresting point, there deffinitly lithium batteries, but the impression i got from the volitile memory SSD is that battery was there to keep it powered up long enough to shift the date to backupdisk, then shift it back to the SDRAM when power resumes (either flash or traditional disc). Oh apparently flash is at current yield, good for at least 250,000 hours and maximum 1,400,000 hours, bit of a gap there.
This reminds me of a conversation i was having last week about data storage, we get new, faster and bigger, but nothing has really been invented that could store data for more than....lets say 40 years. So basically where in a state of perpetually backing up backups (im mostly referring to the digitisation of historical records , libraries , basically huge undertakings of digitisation that ironicaly are being stored on medium that doesnt last as long as the original).