This is getting pretty stupid. I’m not going to answer anymore since all I wanted to do was help the guy that needed help with their DC to DC converter.
But here, the keyword warriors are more interested in being right and trying to point out insignificant things....
all I am interested here is a reply from Remy on how to do it right.
Toasting your 12V battery early may be insignificant to you, but not to others.
There's enough info here now for someone to considsr the tradeoffs seek out what they're after.
You don't care about battery longevity so you are dismissive.
Some people don't care about environmental issues (Californians) or replacing a Chinesium power supply at the side of the road now and then.
I am not going to waste my time looking for 48V stuff for someone's build when most systems are at 360V now and they and you are just as equipped to screen out the specifics to a build. There's enough info in this thread for them to decide what to use.
Some people also need tens of watts, some need hundreds, some even need kW, at 12V nominal. Many have oddball system voltages.
Good luck jump starting another car if you're running 12.0V, by the way...instant load dump into your system when the dead battery car starts. Few think twice about jump starting. This goes the other way as well when you have the dead battery. Most dc-dc converters will fail catastrophically if backdriven.
These builds are bespoke for a reason. Including a low volume "manufactured" car. You were happy with using a DC to DC from a 3D printer or computer (or whatever), including making recommendations based on what you may have built for other people, until the issue of battery killing came up.
Buy your $29 Alibaba dc to dc, and deal with the chance of being roadkill when it fails on a busy highway. Or keep buying batteries twice or three times as often. Or see instant fail during a jump start or hookup to a 12V external battery charger.
These are all the builder's call.