@Alfi666

What is the model, type of battery indicator ?

@griplimited

OK, you need to have some basic electrotechnical skills, soldering iron and a voltage meter.

You need a battery holder for NP-F970 - it can be one of those cheap chargers sold on ebay (about 5-6$)
Dismantle the charger and remove all electronics - leave only the contacts for battery.
Order a "LM2577 DC-DC step up converter" from eBay. Then you can put this converter in the charger.

Onto the input pins of DC-DC converter connect the battery (take care about + and -)

Now with the voltage meter connected to output pins on DC-DC board, set the correct voltage with the blue potentiometer.
You can set it to about 9V - that's working fine for me.
Now just find some cable and connect the output from DC-DC board with the DC coupler that you already have.

That's all.

Only problem is, that you have no idea on status of the battery - so to improve the design, you can order also an "RC battery voltage indicator" on eBay and connect it with some switch to the input part of the DC-DC board. When you press the switch - the indicator will show you the current battery voltage. The battery is OK until it is over 7.0V

I'm powering tmy GH2 with DC coupler (made from 3rd party battery) and with Sony NP-F970 battery. There is a DC-DC booster which brings up the 7.2V of Sony battery to 9V for GH2.

GH2 can run for hours with this setup (already tried 8hrs but battery was still alive).

If anyone interested, I can provide more details

@SisterCities I haven't had a chance to really run it through it's paces. I'm going take it out this week. Initial thoughts - solid build quality, good customer service, and plenty of screw holes that you can attach a rail block to for fitting on rails. One thing I'm a little concerned about is the power cables getting pulled out from the side, but a little gaffers tape should fix that right up.

@5thwall Any update on the GH2 Power Adapter by JAG35?

Can anyone else comment on this unit?

Guys we have been over this surly its been done :-)

Picture with GH1 only, u have to specify GH1 or GH2 for the coupler if u buy from them.

http://shop62712023.taobao.com/?search=y&scid=349401564&scname=R0gxLkdGMS5HMS5HMi5HMTA%3D&checkedRange=true&queryType=cat&stp=7
Talked to the owner about selling on ebay but no new since then...

Jag35 just launched a battery adapter for the GH2 that works with their branded battery. I visited their office a couple weeks ago. I really like what they're doing and I think the quality of their stuff is pretty darned good. Haven't tried the battery out yet, but I'll be purchasing it online tonight and will let you all know how it works. Supposedly the basic battery will last a day or two with the camera. The battery isn't removable so, you'd need a backup source when it drains - another Jag35 battery or good ol' panasonic batteries. Still, I like that it's an all-in-one solution and can be adapted to fit on rails with rail blocks. The downside, in my opinion, is that it's more expensive than some of the alternatives on this page.

Battery adapter: http://jag35.com/gh2poweradapter.html
Battery: http://jag35.com/products/power/jagbattery.html

@DslrDan You mean the coupler? eBay.

I use the Tekkeon battery + original DC coupler with CPM's custom rail mount attachment. Here, I also use it as a light counter-weight on my rig.
While hand-holding I can just slip the battery into a pouch - it's not as 'clunky' as V-mount or Sony type battery solutions.
Costs only $200: Here's the link http://www.cpmcamerarigs.com/Tekkeon_Battery_Mount_p/092_mp3450i.htm

on a tripod I just let it hang... with the battery around my shoulder using the shoulder strap it comes with... but all that will change once I have my cage finished :)