## BMPCC4K + External monitor powered with SWIT batteries??

The place for questions about shooting with Blackmagic Cameras.
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JasonDavis50

• Posts: 11
• Joined: Thu Jan 17, 2019 10:53 am
• Real Name: Jason Davis
Hi Guys,

Was planning on powering the pocket 4k and the feelworld 279s external monitor via a sony 970 battery plate to canon lpe6 dummy battery with these SWIT 8972 batteries linked here:

swit.cc/productshow.aspx?id=6

These batteries have a 7.2V pole tap out the back as well so you can power another device like a monitor. However im told that the power draw of the pocket 4k may be too demanding for one sony 970 battery to power both camera + monitor at the same time. One youtuber Tom Antos even shared that he was using the dc power out from his monitor using a sony 970 battery to power the camera and he damaged his monitor. I'm not sure if this was due to a weakness in the monitor he was using or just the heavy demand from the pocket 4k or both.

Just wondering if these SWIT batteries via dummy battery direct to the camera, and dc out from battery to monitor will be safe to use without damaging the equipment?

Also would like some incite on what the maximum power draw ( in amps or watts ) is from the pocket 4k when working at its hardest like when shooting in high framerates, etc.. and whether there's any room to power anything else during these times?

JasonDavis50

• Posts: 11
• Joined: Thu Jan 17, 2019 10:53 am
• Real Name: Jason Davis
Ok, I've done a little research and math in the meantime so please tell me if this is correct.

Watts = Amps x Voltage

So the camera power power supply is 30W at 12V or so

So according to that formula the max Amps required for this camera is 2.5A.

When powered by the 7.2V canon battery at 2.5A that should draw 18W's or so

The feel world 279s monitor draws 18W's and is powered by a 7.2V battery. Which means that the monitor may need 2.5Amps as well.

So in total the max wattage and amps needed is 36W and 5A's from a 7.2v supply

Now the Swit 8972 battery spec's say that the battery can output 45W and 6A in total with 30W and 4A coming from both the pins and pole tap. So should this be more that enough to power the cam and monitor or am I overlooking something here?

Im going to assume the amperage on the dc output from Tom Antos's monitor wasn't enough to power the camera.

What has confused me though is another youtuber has recommended the powerextra multifunctional battery which is only \$22 that has multiple outputs, however the dc out only supplies around 1 Amp yet he seems to have no problem powering the camera at 4k raw dci. Will this be a safe to use on going I wonder?