I used http://www.ebay.de/itm/LM2596-DC-DC-Step-Down-Adjustable-Converter-Power-Supply-Module-/180915297483 but those boards are all pretty much the same.
I put it in the Cinematics battery pinch without HDMI splitter. There is a lot of space in the housing where the HDMI splitter would be. Added an additional conector to the housing, wired it up, adjusted the output voltage and since then its working fine with my GH2.
$4.2 solution that allow to use any ready market rig power solution with GH1 or Gh2.
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