Volvo sc-805 CD/Cassette/Radio Code : OFF. Extra advice sought

Greetings AAV.

I have an SC-805 fitted to my V40. I renewed the car battery the other
day and then discovered that I had mislaid the code and having guessed
wrongly three times the SC-805 has gone into the two hour sleep.

I have no problems with obtaining the code from the local friendly Volvo
dealer - the problem lies with the two hour period that needs to pass
with the radio receiving 12v from the ignition switch. I have discovered
that it needs to be a continuous two hours not two hours cumulative, and
as I mostly travel quite short distances I'm going to be waiting forever
before it wakes up.

My question is - can I safely remove the sc-805 from the car and supply
12v for the necessary time with it sitting indoors?
I have the connector pinout here and it seems to me that all it needs is
+12v to pin 1 and -12v to pin 2 (& possibly +12v to pin 3).

Before I do anything I'd be very grateful if anyone can confirm that
this method works, or whether I have overlooked something.

All replies gratefully received

Cheers