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

@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

@Alfi666

What is the model, type of battery indicator ?

@SisterCities Looks like they have the sale going on again. So far so good on the battery. Unfortunately can't tell you how long it lasts in the field as my first shoot with it will be in a couple of weeks.

As I've said before, it's nice that it fits on rails with just a couple of rail blocks. I would like to figure out a way to mount the battery on my monopod.

It takes about 3 hours to power up from fully uncharged. I've had my camera set up on it for the last week and a half on sticks and using it once a day for tests. I've had to charge the battery once in that time. So, it's nice that it lasts so long, but I would definitely charge it before going out on a shoot if it's been unused for a few days. That probably goes without saying, though.

The one issue I have is that I am getting a ground loop noise issue when my H4N is plugged into the battery and the line out from the Zoom H4N is fed into the GH2. Jag35 says they are looking into a solution to this for me. This noise only occurs when the line out of the Zoom is plugged into the GH2. Otherwise the Zoom records audio without any issues when the power is plugged into the Jag Battery. It's definitely an issue for me and I'm working on a way to figure it out on my side. Hopefully, they can figure it out on their end, too.

@5thwall Thanks again for all the info. Good luck sorting the ground loop.

How much ampere does the GH2 pull in worst case? Is a 1.5 A Circuit like this one enough?

http://www.conrad.biz/ce/de/product/147044/SCHALTREGLER-9V/SHOP_AREA_18976&promotionareaSearchDetail=005

Thanks, thats a number. So 1.5 A should perfectly do under all circumstances. Just wanna make sure.

I should visit other places more frequently... its just so cozy in here..

I´ve red a bit, seems like Gh2 is quite special when it comes to power supply.
It detects if there is a AC coupler or battery installed by measuring the voltage, in latter case it does some further checks. Worth to read.

Will try with the 1.5 A coupler I found above and report.

Did you maybe check the option "remove 30 min limit" in ptools? Or used any setting uploaded to this forum, since they all have this box ticked... ;)

i am pretty new to he GH2.
On Ebay i bought a Blumax 3rd party.
http://www.ebay.de/itm/250909894441?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
(was unable to find in english, but its there for sure)

EDIT: Mine wont show the Power metering,
but i read there are working blumax 3rd party ones with Metering.

We may able to find working 3rd party ones soon.

One thing, i guess it would be may the easiest and cheapest to empty one of this and connect a emptied charging adapter.
The Electronics have to simulate the original electronics , if this is the case, it should be possible to use some external cells.
Have to test and open one, when we found one, posible a 2s 7.4V may work connected over this electronic, or if he needs single cell sensing al RC Lipo can do over his ballancing plug.
Eliminating the need for over 8.4V.
Maybe

This would electrically the most easiset and with some luck the internal metering work.
All guesses, but may worth to try.

Btw, i got some OTB Batts, read they at least should "work", without metering, sure, cam simply shuts down.
And also have this blumax (damm first i thought he have a working electronic with this batt, but at least this verson deos not).

I wont tinker with the firmware using this 3rd Partys, dont worry (fingers crossed)
but are there problems to encounter, like it has been with GH1 and 3rd party batts?

Nobody has an idea?

I'm glad I found this thread. I bought some of the Chinese 5v/9v/12v batteries to power B4 video lenses with a 12v to Hirose 12-pin cable. I was afraid that 9v would damage the GH2 so instead I bought this 6400Mah battery to power the GH2:

http://www.ebay.com/itm/230715509234?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

The battery puts out a perfect 8.4v in and out of the DMW-DCC8, but when I hook it up to the GH2 I get the dreaded "this battery cannot be used" error. So 8.4v is not enough!! And all along I could have just used the 5v/9v/12v that I already had !! ;(

My voltmeter shows the a/c adapter (OEM) giving 8.8 - 8.9v out the DMW-DCC8.

So now I'm stuck with this bike battery. I don't suppose there is any trick to get it to work.... anyone? 8.4v is so close to perfection! If not, will it work on a GH1? I sold mine a while back but maybe someone else could use it.

Yeah I got it working too using the 5v/9v/12v battery But I have 3 of these 8.4v batteries and 8.4v just isn't enough voltage to fool the camera. I was wondering if there was any way around that, or if it could be used with the GH1. Can't test it, since I sold mine. And I noticed that the hack has "3rd Party Battery" option for GH1 but not GH2 :(