Do I need a 48 to 12 volt step down converter?

[seauubee]

I have installed 2 Allied Lithium batteries in my '05 Precedent. I have run them down to 45% and recharged them a couple of times. Very happy so far.

However I haven't actually completed the install. I did bypass the OBC using CGR-123 (wire A & B) but did not connect the accessories wire.

(please Google CGR-123 as I am a newbie not allowed to post links)

I was told I need a 48 to 12 volt step down converter to run accessories. I bought the converter but now I am thinking I don't need it because I don't have any "accessories".

I have headlights and taillights but are they "accessories"?

The headlights and taillights worked fine before the conversion, why wouldn't they work now?

Should I go ahead and connect the accessories wire?