Equipment Installation

We have a Controlvision AnyWhereMap system in our Saratoga and are upgrading
it to include the WxWorks XM Weather (noncertified version). The PDA will
be replaced, necessitating replacement of the cabling from the PDA holder to
the cigar-lighter plug which also serves the GPS that is velcroed onto the
glare shield. We will use the Bluetooth XM receiver mounted (maybe with
velcro to be a "temporary" installation and not a modification of the
airplane) inside an unused panel space or in the nose baggage compartment.
There are a lot of openings for the Bluetooth signal to get through, so we
are going to try that. We will reuse the existing GPS.

I would like to connect up a gel lead-acid battery to provide backup power
to the AnyWhereMap system for backup navigation. I would like to pick off
ship's power from an existing unused 5A breaker, put a SPDT NORMAL/EMERGENCY
switch on the now-blank panel over the unused ADF slot, and connect the
battery to the other side of the switch. We will remove the backup battery
for charging external to the airplane. I can put an inline fuse in the
battery lead at the battery.

Question: Does this kind of installation work require A&P or IA signoff?
Does it require FSDO approval? Does W&B needed to be signed off?

Stan