After doing more research both in the manual and with our staff here the use
of nicad batteries is not recommended at all. As Joe Ratner from Tandy
mentioned in his message, the use of nicads may make the machine operate in a
strange manner. As for the unit shutting itself off or just going to sleep,
it does indeed shut itself off. You do have the option to set the time that
you want the unit to shut itself off. This can also save battery life. Hope
this helps.
Scott CASIO Tech Support Subj: No NiCads?!?