How do you integrate the 48V system with the existing 12V system when doing aftermarket/DIY work? Do you add a 48V inverter? A buck-boost DC-DC converter? between the battery (or main fuse block) and the 48V system?
Do not attempt a hybrid system with different voltages DIY
In an industrial setting it can be done but you need an extremely well designed and made termination point for one system and an interconnect for another, I’ve seen customers using floating grounds (and negative voltages) to enforce it
If upgrading to 24V or 48V I recommend having a solid grasp on circuit protection first, and if you have concerns, pay the 30 minutes or so labour for an automotive electrician to inspect it
In an industrial setting it can be done but you need an extremely well designed and made termination point for one system and an interconnect for another, I’ve seen customers using floating grounds (and negative voltages) to enforce it
If upgrading to 24V or 48V I recommend having a solid grasp on circuit protection first, and if you have concerns, pay the 30 minutes or so labour for an automotive electrician to inspect it