I intend to have some GH3's and GH4's as stand alone cameras in the field for a project. They have to be powered by large 12V batteries. Have been looking for (and found) a 12V>8.4V converter to match with the available Panasonic dummy battery.

However, I notice the original battery is 7,2V, the AC adapter that comes with the camera delivers 8.4V and a Switronix D-tap cable for the GH3/4 is 9,2V. Which makes me wonder, would the camera also be able to deal with 12-13V, so no need for a converter?

Can't find any technical information about the range of voltage the camera can handle. Maybe someone on this forum knows?

Lumix GH4 (http://www.switronix.com/products?page=shop.browse&category_id=56)

Hi I have ordered some 7809 9v regulators for 1 amp. I will mount it in the adapter for ext. power if I can dismantle it. Otherwise I will put it before and supply it with 12-15V from a battery. I would not count on the camera can handle 15-16V as Lion batteries supply. I will let you know how it goes - I have tried 7,4V on the battery-adapter - it do not work!

Hi Cees,
I purchased a Panasonic dummy battery (DMW-DCC12) for my GH4 to try with an external battery but it did not work (as I half expected). It is designed to work with a Panasonic mains powered supply that contains the necessary chip. However I did find a third party dummy battery (with chip) that works with a battery. This dummy battery does not seem to have a built-in regulator but two Li ion batteries in series give a voltage of ~ 8.4 volts. There are a lot of 18650 sized Li ion batteries (18 mm diameter x 65 mm long) available in various capacities. The NP 750 etc batteries are a nominal 8.4 volts. Some have a built-in cutout that comes into play when the battery is over-loaded or when the voltage drops to a certain level. The cutout is reset when the battery is recharged.

I would like to thank you for your tip on the Canadian converted GoPro. I now have one set up on a small fluid damped boom to use for macro work. Its small size makes close-up work much much easier.

I bought a battery pack and a dummy battery and fried a GH2, but you already seem to know to be careful.

I did the same with a gh2 but had it fixed for about $100 - I didn't check the polarity

Hi
Today I disassembled my DMW-DCC12 and mounted a LM7809 DC regulator in it. Mounted a XLR 4 pole female on the cable and now I can just put power from my different V-Lock batteries into the GH4. So far it have worked the hole day. Only problem I have now, is the limit on 30 min. recording time.....

Hi Bo,

Thanks for coming in. You always seem to be working on the same things as I am :-)

Is the LM7809 an expensive solution?

I intend to get several GH4's in the field. They will be triggered by a motion sensor. It will record for a limited interval after triggering and then stop. At next motion it will start again. So the 30 min is no problem then anymore. Working that solution out now. Found a supplier for this, but the system still needs some adjustments to get it working properly with the GH4. Hope it will be solved by next week.

If we manage to make the motion sensor also get the GH4 out of SLEEP mode, there is no need for additional power. The camera will then only be on when it has to film and go to sleep after a minute. I can replace the battery every other day. Not sure yet if we manage to get this working.

If we do not manage to get the camera out of SLEEP mode, I will have to keep it on. In that case I have to power it with an external, large battery. The LM7809 might be the solution then.

I have tried the DMW-DCC12 with 7,4 volt but both the GH3 and the GH4 would not accept this voltage because the camera would expect a battery when at this voltage. The camera cannot get a data connection with the battery because it do not exist on the DC power adapter.
At 9V the camera expect a DC connection. I have read that it will not go to sleep at this mode - but I have not tried it yet! For you the 30 min limitation could come in handy for your action.

I bought 10x LM7809 for 5 euros so it is not expensive and it is very easy to mount if you kan solder - three pins: 1= input 2=ground 3=output

5 Euros? Great.

When I need this solution it doesn't matter it won't go to sleep, because I only need this solution when I can't get the camera out of sleep anyway with the remote PIR trigger.

If the solution is going to work the way I want I can choose an interval of for example 1 minute for recording. So motion detection starts the camera to record and one minute later it stops. When PIR still detects motion it will start immediately again, if not it will go in sleep mode (after time has passed as set in camera menu). Till PIR detects motion again, wakes the camera up and starts recording.

That is at least what we attempt to achieve.

Bo, do you think I can also use large 12V batteries to power the camera with the LM7809 installed?

Hi
Today I disassembled my DMW-DCC12 and mounted a LM7809 DC regulator in it. Mounted a XLR 4 pole female on the cable and now I can just put power from my different V-Lock batteries into the GH4. So far it have worked the hole day. Only problem I have now, is the limit on 30 min. recording time.....
Bo, a word of caution. The LM78xx family of voltage regulators is so called "linear" kind, which means it simply dissipates the excess power on its body to bring voltage from 14.4V down to 9V. They work OK with small currents; the GH4 uses fairly high current while running, so the regulator would be getting hot dissipating that energy. I recommend you check how hot it runs while the camera is recording, as it can damage the camera just by overheating from inside the compartment. Also, by wasting power you cut down on the run time - it is not an efficient way of doing things.

Hi Bo,

I seem to be missing something in this story. As I mentioned in my post above I tried a DMWW-DCC12 using a DC input of 8.4 volt. For about a second it looked as though it would power my GH4 but then the start-up screen image was replaced with a ‘You cannot use this battery’ or words to that effect. I was not surprised as the description of this product was rather vague and my dealer was of no help either. The DCC12 appears to be designed to work with Panasonics rather pricey mains operated power supply. To use it in the field one would need a battery supplying an inverter connected to the Panasonic mains unit connected to the DCC12 and then to the GH4, all very cumbersome. Fortunately I found a third party product that works with certain batteries so I now happy.

However I am left with a DCC12 that does not seem to behave as yours does. Can anyone else get the DCC12 to work with a battery? I just want to know if my sample is faulty.

I can back up Alex's comments on heating issues with voltage regulators. I have used LM317T regulators as the basis of 'dummy battery' for still camera flash units. Even with a voltage drop of 2 volts they got very hot which surprised me as I was only replacing AA cells.

Hi
I mounted the LM7809 on a piece of metal internal in the compartment and it gets warm - I have not calculated the power loss as I do not know the current. Otherwise it could be mounted in a box outside the camera.
And yes it would be best with a battery with as low voltage as possible to minimize the power loss but my big camera batteries has so much power that there will be no problem.
I have had the camera recording for several days now and it still works.
Another way to do it, would be to mount the LM7809 inside a Dynacore D-C adapter. There is a lot of space in it - I have old model without HDMI connections but cannot find it on their webpage - only the new one. dynacore-china (http://www.dynacore-battery.com/productshow.asp?id=202).

There seems to be a voltage where the camera shifts from seeing the power as comming from a battery or from a DC converter. The voltage, as I have wrote before, must be somwhere between 8,4V and 9V to make the camera seing it as comming from a the DC converter. If you are at 8,4V and below the camera tries to communicate with the battery through the extra connections that are on the battery - there are no such connections on the DMW-DCC12 and 9V seems to be a fine choice.

"I have not calculated the power loss as I do not know the current" - just fyi the camera uses 0.5-.8A @7V to operate; a typical Li-Ion battery is 16V fully charged, 14.4V at 1/2 charge state. So we have about 5V-7V voltage drop on the regulator, or 3W-5W power dissipated, meaning the power supplied by the large external battery is split about 50%/50% between the camera and useless waste dissipated as heat.

Thanks Alex
Have you better proposals how to use our standard Lion batterys with the GH4 to spare some loss?.
I have tried the 12V outlet in my Dynacore D_C adapter and it works fine too - to split some of the heat.
A LM7809 is also mounted on one of the outlets so I can supply the camera directly from that.

PM sent, trying to keep business separate from good conversations :-)

I have decided to play it safe and go for a Switronix cable, as suggested by Phil Goetz.

http://www.switronix.com/products?page=shop.product_details&flypage=flypage.tpl&product_id=263&category_id=56

Hi
That cable is great. Unless there are a switchmode supply inside the case it will give the same result as with the LM7809 regulator. :)
Bo

Hi guys,
Does anyone have any feedback on this-
External Rechargeable Battery for Panasonic GH3 GH4 Video 8500mAh DMW DCC12 | eBay (http://www.ebay.com/itm/External-Rechargeable-Battery-for-Panasonic-GH3-GH4-Video-8500mAh-DMW-DCC12-/181134841252)

Or, can anyone point me in the right direction to something similar?

Hi
That cable is great. Unless there are a switchmode supply inside the case it will give the same result as with the LM7809 regulator. :)
Bo

I think that they will have another solution with no chance of overheating. At least I hope so for more than €70.

I have ordered one to test, which I can do later next wek. Will keep you informed.

My solution is heating - not over-heating. The plastic is warm but not hot - there is a built in over heating control in the LM 7809 so I am not afraid. But this solution with a cable ready for use is smart and not expensive so it will be fine. I would have bought it too if I had known it existed!