Stereo voltage converter + 12v to power amp

[sigfla45]

Ok so my new Sony head unit plus my bazooka sun amp seem to be maxing out my 30 amp converter. I can lower the max volume and it won’t cut out but I am concerned about how it will behave as the batteries run down or I use more lights. I am powering all of my aux electronics via a blue seas buss bar hooked up to the 30 amp converter. I used to just use a standalone 12v agm battery. If I hook up my 12v agm battery to the positive and negative main terminals of the buss bar I will:
1. Have constant 12v power
2. Help eliminate the excess draw on the 30 amp converter
3. I will have to charge it separately as I did before
4. Charging it shouldn’t back feed anything into the 12v converter bc it would be off but if it did it would only be connected in parallel to the 12v output anyway

I was initially wary of this but assuming my logic is correct it shouldn’t pose an issue. Can anyone with more experience than me tell me if my thought process is correct? I don’t want to fry anything and don’t want to back feed 12v into the 48v pack through the converter. Even if I turned the converter on while everything is charging I can’t imagine I am doing anything but parallel connecting 12v to 12v.

[sigfla45]

I could also hook up my kayak battery pack if necessary and have a totally portable solution and eliminate any permanent wired battery. I would just pull it out or turn it off while charging the 48v pack

[sigfla45]

Well I just tried it using my removable kayak battery box. It works and didn’t seem to affect my converter any. I did not try and hook up the 48v charger while it was plugged in though. It didn’t resolve my volume cut out problem though. It seems my Sony unit only does it with the BT audio connection. The radio could go all the way to 50 max volume. BT cuts out depending on bass at around 38-39. It’s still plenty loud but I will have to do some more research as to why it cuts out