Hi DavidCyr2000,
You have indicated that your end system doesn't need to source supply such heavy currents for long duration's. Since one can't get more power out than the available power in.. then surges are usually overcome by adding Large Caps as energy storage containers to the Input side to accommodate surge requirements.
The devices I suggested earlier in this thread do not produce Free Power. But they sidestep Ohm Law as far as heat loss is concerned. I convert 18VDC to 5VDC all the time in my circuits using these. Power lost to heat is minimal.
If your power output exceeds the load capability of the battery source such that the battery output drops below a specific voltage then it seems your are fighting an up-hill battle.
You indicate 1440 watts in and 1440 watts out with no loss.. ok maybe.. But how long can the source supply 1440 watts of power? How fast does the Battery output degrade under full load? Batteries have a built-in resistance that limits output power rather dramatically and rather quickly.
In reference to your Gif link above..
I used the following circuit to produce -12V from my 12VDC source:
I turned it sideways to keep as much detail as possible.
Right Click on it and open in a New Window.
I run it at 8KHZ and it allows about 250mA loading before the Caps (470uF) can't sustain it. Getting the driver Transistors to switch properly without them biting each other can be a bit tricky...lol.
I think such a circuit is a dead end for your massive power requirements.. to be honest.
Regards,
Dave :^)