He/she already changed it, I'm not sure if he wants to reset and download. Just to fix it and it may not work? Once you reset, there is no changing back. If it fails, you lost your previous data forever.
Have you droped your tamagotchi latley, or mabey even into water? (I have done both <_< ) If so this may be the case.
This happened to my friend Kutchipatchiman45 on his old v. 3 :furawatchi: He finaly got it working by reseting it, hiting download, and then leave it aside for awile , and very quickly feed it when it gets hungry or else you have to reset again . Then it should stop saying the battery is dead .
Hope it helped! Catlover5853 and Kutchipatchiman45