Mex, you and I "get it" and understand the short comings, the problem is it seems that lots of others just don't "get it".
While technology has advanced with much more efficient switching power supply type of DC - DC boost/buck systems, you simply end up with wasting a lot of the energy in heat due to the line losses.
The end result is putting much more stress (and heat) on your most critical must run part of the system (your vehicles battery and charging system).. Which really was never designed or intended for high current charging over LONG periods of time.
Sure, a 300 HP engine could produce up to 222 Kw of energy, but why in the world would one wish to beat the darn thing up is beyond my comprehension..
High current auto alternators are not cheap, towing is not cheap..
So, if one REALLY insists on using a "cannon" to swat a "flee" then you should consider doing it with the LEAST harmful impact.. That amounts to using a MORE efficient conversion process.
12V to 120V inverters are cheap and plentiful and extremely easy to find, DC-DC not so much.
14ga-12Ga wire is cheap, 2ga-1/0 not so much.
Boosting DC will result in a heavier load on the starting battery and alternator with only marginal gain, wasting a lot of power over the resistance of the wire in heat..
If you want heat, I am sure there ARE better ways to go about that..
In motorhomes and even trailers, the house battery charging is not meant for fully replenishing a totally dead house battery. It is there to help keep the house battery which is nearly or fully charged TOPPED OFF WHILE TRAVELING.
The real charging workhorse for HOUSE BATTERIES IS the CONVERTER when you are plugged into shore power..
So why not take advantage of what is already there?
Just add the 120V inverter and you ARE done.
