maybe u read it wrongly ?
its not Eveready
but Ove-aready.

not so simple, rechargeable 1.2v only, non-rechargeable 1.5v, some device that sensitive to voltage will assume you low on power and cant operate normally, ie my old sony camera, the flash will take like 2-3 seconds to charge if use 1.5v alkaline batteries, but if use the expensive eneloop batteries, will take at least double the charging time, sometimes even triple.

or some remote control the brightness of the display(black text), almost cant visible when voltage low.

i hope those eneloop do have 1.5v version.