The reason, I assume, is because the firmware data is copied from your flash card to some internal memory during the upgrade, and if that fails due to a dead battery at a critical point, your Bookport is now a door stop. Since I guess you prefer a Bookport, rather than a door stop, making sure battery levels are up to snuff before you update firmware is, well, critical. <smile> -Brian On Nov 15, 3:23pm, "Eric StevenS" wrote: } Subject: [bookport] Question on Updating Firmware } In reading the manual, there is a warning to never attempt a firmware update } when using rechargeable batteries. } } Why is that? } } Just curious. It does say to check that batteries are at at least 50% } strength. Is it because rechargeables may not report accurate capacity, as } was warned earlier in the manual. } } As I say, just curious. } } Eric } } >-- End of excerpt from "Eric StevenS"