Ugh, sounds painful. I wonder if you got the polarity reversed when you wired it up? In that case the power regulators inside the camera might be blown or it might be as simple as a small fuse blown in there. According to the writing on my gh1 it works with 9.3volts so I don't think excessive voltage was the problem. Sounds like back to Panny for repair time. I've been told that the repair station in Mcallen Texas gives good results.

Don

The RC battery pack has a nominal voltage of 8.4v (1.2 x 7)...but in reality, after charging (and depending on the type of charger you use) the terminal voltage of the NiMH pack could be as high as 12v or more. That, combined with the low internal resistance of the adapter/camera would be enough to blow a lot of IC's and component's.

I fear that repair might be more expensive than a new camera body...

@CobyD,

What brand adapter did you buy, and did it ultimately work?

What should the polarity of that adapter's tip actually be in order to work with the GH2?

Thanks guys, I tried to be extra careful, but it probably was the polarity. I think the battery itself was wired wrong by default. I dont understand it though, isnt it the job of the DC coupler to take care of this???

Anyways, does anybody know if the camera even has a fuse or power regulators which can be changed by service?

It would be horrible, if the whole body is destroyed...

Ok this is a WARNING to everybody who want to use a custom build battery pack!

Be super careful and measure everything through, from the battery till the very last pins of the DC coupler, otherwise you will destroy your camera, like I did!!!!

I wanted to check what happened and just replaced all connectors with XLR and measured everything with the Voltmeter. I noticed the following:

Normally all cables which carry the + voltage are marked with white color. The original Panasonic Power Supply carries the + voltage on the white marked color.

BUT:

The original Panasonic DC-coupler carries the minus on the cable which is marked with white color!

This is insane! Panasonic switches suddenly the polarity in the connector which connects the DC coupler with the power supply. Probably a very mean trick to prevent compatibility

Can anybody confirm this?

I found that even though 8.4v works, depending on the features and outside temp(yes the temperature), 8.4v can be too little.

When the camera would get hot, 8.4v would not power the camera.

Or use a potato. I remember from my schooldays that if you stick a couple of wires about 1cm apart into a potato, the potato will turn blue around a wire of one polarity. Can't remember which but I'm sure I have a potato somewhere so I could test it and report back. Of course, you need to carry a potato around with you and wait a bit for it to work, but that's a small price to pay. Can't be fried or sauteed, has to be raw.

UPDATE The potato turns green around the negative wire. So you need never worry about polarity again!

CobyD: I orderd a Dynex universal camcorder like this one: http://www.ebay.com/itm/Dynex-Universal-Camera-Camcorder-AC-DC-Power-Adap-DX-UA-/260765841802?pt=Batteries_Chargers&hash=item3cb6daf98a#ht_1450wt_1141

It works! (I checked the polarity before I used it)

If anyone orders one, make sure it comes with the straight tips, the ones that came with mine were only the speciality ones, but after I contacted the seller, they sent me the correct one (as pictured far left bottom, dimensions 4.75mmx1.75mm)

I have built my own battery adapter which allows me to use Sony F970 batteries with my GH2. I have an electrical engineering background and I was very careful about how I designed my adapter. As has been stated the fully charged voltage of many batteries can be well excess of the rated voltage. While this in of itself may not cause damage to the GH2 I had no intent of letting my prized little GH2 see anything other than a nice clean compatible voltage level.

So I decided to use a DC-DC converter in my adapter that steps the voltage from the battery down a little to be more compatible with the GH2's normal operating level. A Sony F970 has a start voltage of about 8.4 volts and drops to 7.4 for a considerable amount of time. The problem of course is that most DC-DC converters need some amount of "pressure" or voltage difference between the input voltage and the regulated output voltage. I wanted to supply my GH2 with a stable voltage of some level for the longest period of time.

To do this I first ran a normal Panasonic battery down to almost empty. I then measured the voltage output from the Panasonic battery and found that at the last Bar on the battery gauge the Panasonic battery was reading 6.8 volts. Using this voltage I adjusted my DC-DC converter to output 6.8 volts. By doing this I know that my GH2 will never see more than 6.8 volts of power from my Sony F970 battery adapter. So when I plug in a fresh F970 with a voltage level of 8.4 volts my adapter steps that down to 6.8 volts and holds that voltage for a very long time.

In testing I have been able to run a stock GH2 for 8 hours of virtually uninterrupted recording. That was having it record at 24P H looking at a TV screen for changing content. Each time the card filled I would format the card and start recording again. I think 8 hours from one Sony F970 battery is pretty good.

The tough part was the actual connection to the GH2. I used a cheap third party battery to create my own power adapter. I found of course that the GH2 does not like to get just a voltage levels it also needs a special signature from the battery to allow the camera to operate. I had to incorporate a small mother board from the third party battery into my adapter as well. This was fairly tricky as there is little room between the contacts of the normal GH2 battery connections.

I have never done a DIY video on my adapter for this reason. I am too concerned that the connections I used via the old third party battery were to delicate for many to do with out potentially damaging their GH2. I use my adapter often and love the long run times.

In general please be careful when trying to adapter any type of power system to any camera or device. Always check the polarity then check it again, and check it again. You can check it a million times, you can be wrong only once.

@markmark1 - Do you set the Dynex charger to the 8.4v setting? I'm looking at getting one. Here are the specs: http://www.dynexproducts.com/cms/documents/DX-UA_09-0318_QSG_V1_EN_Final%20Press.pdf

and I'm assuming the DC input to the DC coupler needs to be regulated, right?

@evero
For anyone feeling adventurous, I used a very small Texas Instruments circuit to convert my ~12V battery pack to 9.3V for my GH1. Depending on what country you are in, you might be able to obtain a free sample from Texas Instruments (I was in the UK when I obtained mine) I also have a 9V output which runs the camera just fine.

More details here: http://jordanofoz.com/?p=20

@evero
1. No - input voltage is too high?
2. Looks ok - no mention of efficiency though. I think it's a pretty inefficient circuit.
3. This looks like the efficient variety (can't remember all the details now, it was ages ago I looked at this stuff)

I would get something like this as mentioned in the other thread:
http://www.ebay.com/itm/5V-9V-12V-USB-Super-Capacity-Recharge-Li-ion-Battery-/280726420534?pt=US_Batteries&hash=item415c993c36

Unless you've already bought the one without 9V output?

@arvidtp

I set it to 8.4v.

I'm not quite sure what you mean by "I'm assuming the DC input to the DC coupler needs to be regulated"

The dc coupler (the bit that looks like a battery and goes into the camera) just feels like a hollow box that connects the wires from the coupler to the camera appropriate contacts. That's why we need the Dynex thing to power it at 8.4v.

Make sure the seller includes the 4.75x1.75mm tip, that's the one you need for this. I had to get the seller to send it to me after the adapter and other tips arrived.