🚀 go-pugleaf

I am trying to add battery backup to one of my sound modules, and I was
wondering just how difficult or more precisely what the best way is to
go about it.  From what I understand, you locate all temporary memory
IC's disconnect the +5 from them, and then attach their power lines to a
circuit which switches between normal operating voltage during power up
situations and a 3.3 volt lithium during power down situations....is
this a correct assumption?  And if so what do you think the best
configuration is? Should I use a zener with a voltage comparator which
switches off the normal power and on the battery by way of diodes when
the voltage drops too low?  Any insight would be much appreciated.  I am
a computer engineer, but haven't had much exposure with battery backed
up ram systems (at least not at this level...)


Thanks,
E. M.