Gdetrailer wrote:
No, that is not the way it works.
Yes it is the way it works.
The problem is that if you are drawing 20A, you would get a voltage drop between the TV and the TT. The drop may be as little as 0.5V but that is enough to not be able to charge your battery. Its the same issue in many RVs where the converter is too far from the battery.
These chargers sits close to the battery and eliminate the issue of that 0.5V voltage drop. DC-DC converters of this type are 98% efficient so don't know where you get this 40A cause a draw of 60A.
You can do the inverter method as well if you wish. A DC-DC converter does the same exact thing as an inverter but at much lower AC voltages.
Its the users choice to use the charger's built in inout voltage cutout or an ignition controlled relay. That's a minor issue.
