babock wrote:
MEXICOWANDERER wrote:
As far as TT is concerned, this device cannot manufacture watts.
It gets rid of the problem with voltage drop. You could pull 20A with a high voltage drop through the wiring between the TV battery and hitch connector yet still get the full charge voltage required to charge the TT battery.
No, that is not the way it works.
You are simply MASKING the problem and possibly creating an overload of the wiring.
To get 40A at the battery using a DC-DC converter you will waste a lot of energy in HEATING the wires.
The DC-DC converter may be able to boost the voltage enough to overcome the line losses but at penalty of drawing a lot more current the vehicles battery and alternator..
I suspect to get 40A at the house batteries the DC-DC converter will be drawing 60A or better.
By using an 112 to 120V inverter you will waste some energy, but not near as much as you would trying to force low voltage high amperage DC through a long run of wire.
PROVEN TECHNOLOGY.
That is why the AC power grid goes to all the hassle of high voltage distribution with high to low voltage transformers at the service drops.
If it wasn't for the high voltage the power company would have to use wires thicker than a human and that would only get you a few miles of distribution. Instead, they can deliver enough current to power tens of thousands of homes and businesses for thousands of miles using a wire about the thickness of you finger..
MEXICOWANDERER wrote:
BUT, it would have to be ignition controlled to neuter effects when the alternator is not charging the chassis battery.
At least one model has a voltage threshold where it turns on above 13.2V and turns off when it gets below 12.7V so that would alleviate the problem with the charger discharging the TV battery.
I would not want to "depend" on the fuzzy logic on my main starting battery.. That IS suicide to say the least.
A hard on off of a relay WITH the vehicle ignition will ensure that you starting battery will never be flattened..
It would only take ONE TIME getting stranded somewhere to fully change your mind..
My comments in red above..
