X70 external battery

[Dan Gunn]

I have modified an old shoulder bracket for my X70. Now the bracket has a V mount on it to accommodate my BIG old Sony batteries. I wanted the extra weight behind my shoulder for ballast.

This battery will run my Zlight, Small HD monitor and the X70.

Has anyone seen a dummy battery or a power adapter for the X70?

[Donald McPherson]

Do you need a dummy battery? I would just plug it into the charging point as though were charging camera.

[Dan Gunn]

"Do you need a dummy battery? I would just plug it into the charging point as though were charging the
battery"

That is why I need an adapter/power cable or a dummy. I do have a power supply but the cable can not be removed.

[Donald McPherson]

Take battery out and plug the charger in. Does it work.

[Sauro Scroglieri]

that's a solution I've been considering for some time (my current counterweight is a 2 Kg scuba diving block) but... X70 power supply output is around 8V while the V-Mount battery is 14.4V: how can we match the two?
can the X70 swallows the 14,4V without stomach troubles?

[Paul Anderegg]

Most "dummy" batteries used for external power, have the transformer inside to reduce the voltage to the cameras specifications.

Paul

[Sauro Scroglieri]

thanks Paul, I didn't realize that!

[Dan Gunn]

Evidently the X70 dummy battery does not exist. I have an off brand NP-FV100 pack that I am going to carefully/safely open up, toss the lithium batts and see if I can add a circuit.

Will report.

[Jeff Pulera]

I've found actual X70 power supplies on Ebay just now for $7.50-12.00 range. As a source for the power cord - cut it off and wire it to your DC power/batteries?

Thanks

Jeff

[Dan Gunn]

Jeff, I still need to transform the voltage. I am still working on that problem.

Thanks

[Christopher Young]

As Jeff says buy one of the X70 type power supplies of eBay chop of the cable and connect it to a suitable power supply. I used one of these V Lock plates that has a regulated 7.2 volt out. I cut, soldered and heat shrunk the 7.2 volt 90 degree plug with about six inches of cable to the cable cut from the eBay X70 type power supply and voila it works a beauty.

https://goo.gl/5TtZJm

First off I tried using Sony FP-970 batteries as a power source as they were also 7.2 volt. The problem is the X70 detects the voltage dropping from NP-970's 7.2 volt and as it is not getting any feedback from the chip in the battery it will all of a sudden with zero warning just cut out. Sometimes with rather nasty consequences to the recording going down on the card.

The X70 requires a constant non dropping voltage if there is no battery feedback circuit to make it think it is connected to a regulated mains power supply. The beauty of these V Lock plates is that they have a constant regulated 7.2 volt output. A fully charged V Lock can come of the charger at 16 volts. If you 'D" Tapped that to the X70 you would fry the X70's power input circuit. Using the regulated 7.2 volt from the battery plate I can run all day on a 150 Watt Hour battery and still end up with three of the four battery indicator LEDS still showing that there is 75% capacity left.

If I'm running around shooting I just use the NP-FV100's. I do a fair amount of long conference and seminar streaming shoots and this is where I use this V Lock power alternative. The V Lock plate and battery sit in a Bum Bag (I think in the States you call them Fanny Packs) slung around the top of the tripod legs.

All in all it works a treat.

Chris Young
CYV Productions
Sydney

[Dan Gunn]

I found the input cable. Now I am looking for an adapter that I can modify. All I have to do is rework the cables. There are plenty of adapters available.

[John Mitchell]

You need a step down (buck) DC-DC transformer. It needs to have an input range of 12 - 16.8V (at least - because a fully charged V-lock should sit close to 16.8V) and you'll need to adjust the output to 8.4V DC. It needs to be capable of at least 1.7 amps as that is the rated output of the supplied Sony power adapter. You also need to ensure that you get the polarity right - you just need the power adapter and a multimeter to check which cable out of the supply you chopped the end off is positive.

You also need to get the polarity right on the input side or you'll destroy the module - most v-lock plates have a D-Tap and that is often the best cable to make although for my FS-700 I just wired the cable directly into the buck converter (and because I just bought a V-lock plate of fleabay I wired the module directly into that. You can power your other items off the D-taps.

Here's a couple:
DC-DC Buck Step Down Voltage Regulator Module 3.3v 5v 12v 19V 24V 5A Adjustable | eBay

DC-DC Buck Step-down Converter Adjustable Module 5-24V to 3V 3.3V 5V 9V 12V 2A | eBay

I would personally go for the first one - it comes with a heatsink which will probably be necessary, and looks a little better made. Ripple shouldn't be an issue as your source is a battery which is pure DC. You'll need a small case as well and some way of mounting it on the v-lock plate.

[Martin Archer-Shee]

I too am looking for an external battery pack system.

I do not have the PXW X70 but the FDR AX100 and using the FV70 is not giving enough time. Have after market FV100 but am not pleased. A Atomos power station was suggested but they do not have a dummy to fit the AX100/x70.
I searched on eBay and there are lots of dummy battery couplers for Sony 7s series but nothing for anything using a FV70/100. If there were a dummy coupler one could use the Atoms system with the Sony L series batteries. Even cheaper it would be possible to use a battery adapter plate for L series batteries such as this

Battery Back Pack Plate Adapter for SONY NP-F 970 F750 F550 BMPC BMCC BMPCC R1B0 | eBay

Total cost of a dummy coupler (if existing!!!) and adapter plate would be under $50. Add your L series batteries and away you go.

Dan, if you get the FV100 apart and strip it, I do not think you would need any circuitry if feeding from a L series F960 for instance. Correct me if I am wrong. Obviously one needs to connect the right wiring to match the L battery.

Martin

[Christopher Young]

As I previously mentioned I have tried this route with 970 batteries on an external plate.

As there is no intelligent feedback to the camera's internal battery interrogation system from the external battery supply there will be problems. As soon as the camera detects the input voltage dropping on what it believes is a constant voltage external source, e.g. an AC power supply, it will cut out. Using 970 battery plates and we found 20-30 mins run time is all you will get on an X70 or the like.

To keep the camera alive it must be supplied with a constant voltage between 7.2 to 8.4 volts. Sony don't guarantee anything outside of this voltage range. 9 volt is considered too high. Some shooters have had success running 9 volt supplies but as Sony stipulates it is outside the recommended range. Sony went as far as to tell me that this applies to all their cameras that use batteries with a nominal 7.2 volt rating.

To do this with external batteries you need to go through some kind of DC/DC converter that will maintain a constant voltage to the camera. Start with something like a V-Loc plate with a regulated 7.2 to 8.4 volt constant level output, available on eBay at reasonable price, and the camera runs all day, and does so safely within spec.

This one has a 7.2 volt output plus other useful voltages for monitors, lights etc and costs less than a genuine Sony NP-FV100

USB BP V-mount Power Supply Battery Plate Automatic Lock For DSLR Camera Rig | eBay

For me this solution is working 100% safely and allows the cameras to run all day on long shoots like all day business seminars. Also it's a good feeling knowing that all is running safely within the manufactures specified voltage range and that you have hours of run time to spare.

Chris Young
CYV Productions
Sydney