Does the 'temporary memory'...
...on a receiver/head unit always require power? I assume that it does. And going on that basis, if someone needs to remove the battery, will attaching the cables from a battery charger to the +/- cables suffice to keep the memory, umm, memorizing? I'll add that my charger is ancient but works well for basic charging.
Could it do damage, especially to a new receiver with add-ons which I assume will have numerous specific preference settings?
Actually I'm planning on getting a Harbor Freight battery jump starter which would probably work better for this.
To make it clear, the receiver would not be turned on.