I just received one of these....It's nice. Wondering if I should get a big SDXC card or use multiple SDHC cards. But the real issue is...how long with the built in battery in this device last? It's not like a phone...I only keep those two years...but this thing, I might want to have it around longer than 2 years. Anyone have any experience with longevity of the battery in these? Dang: Meant this to go in the general forum.