I saw that Battery unit on AmigaKit. Almost ordered it before finding coin holder at surplus store.
Nice, but goes on Motherboard and hard to get to battery (after Drive Cage goes back).
My coin battery holder would also fit perfectly on the motherboard. All I would have to do is solder in the tiny diode on the backside. (Diode is only thing on PCB)
But to solder either I would have to take out the motherboard to solder from the backside (didn't want to risk doing the MB takeout)
The breadboard is solidly in place (easy access for replacing battery 11 years from now

). Plus can take out battery if I want to.
(Coin batteries can also leak, damaging the mother board. This is safer)
I glue gunned all the components, wires on the Breadboard. (after taking that picture). Nothing is going to move. Can peel off soft glue if I want to.
This is just power, not high speed data connection. (Actually there isn't any high speed data in this A2000 much anywhere! )
So will be quite fine for permanent setup. (Total cost $5 with battery)
I'm actually thinking of doing something similar for the Kickstart ROM Chip, which also hard to get to.
I know AmigaKit sells a nice switcher that will flip Chips using [CTRL]-[AMIGA]-[AMIGA] keys.
But a simple dummy chip (found it in my parts box)-> wired to ribbon cable extender to a 2nd easy access socket/breadboard will keep me happy.

But that's a possible, later project, if I really need/want dual kickstart ROMs.