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Nikon d7100 DC power

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#1 Gschnettler

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Posted 01 August 2020 - 07:35 PM

I assume the camera runs on DC power. And I have a nice large battery with several outputs including DC and AC. But I don’t see the point of converting to AC only to convert right back to DC. But it looks as if most Nikon external power supplies are AC. Is anyone aware of any that are DC?

#2 AgilityGuy

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Posted 01 August 2020 - 10:45 PM

Batteries supply DC power so yes that’s correct.  Depending on your particular power supply it would likely power the camera but depending on the voltage of the battery you may need a DC-DC converter to deliver a nominal 8 Volts to the camera.  There are several companies that make combination supplies, like Kendrick Astro which sells a dew heater controller with an accessory port to power cameras.  There are other companies that sell battery adapters like Tether Tools, I personally cant recommend this one in particular as the system wasn’t cheap and failed in about a year.  

 

Several people here on CloudyNights have made their own that apparently work very well.  A search would likely pull up several of them. 
 

Good luck!



#3 otoien

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Posted 01 August 2020 - 11:46 PM

Some information I posted in another forum regarding powering D7100 and D500:

https://nikongear.ne...p?topic=8114.50

 

I was able to power the D7100 for 8 hours and 37 minutes (846 exposures, each 30s) at -25°C with a battery bank based on four 3.4 Ah 18650 cells. There are some more details on page 1 of the thread.

 

Generally a problem is that power draw of D7100 and even more so with D500 is quite high during the fast mirror movement. The battery bank and the needed DC-DC converter's safety feature might cut off when amp-rating is exceeded, even if the period of high power draw is very short causing the camera's shutter/mirror mechanism to lock up. A new shutter actuation is then needed to clear the locked up state. So I added a super-capacitor circuit to level out the power draw. If you can find a battery bank that has 9V output directly with adequate amp-rating you might be able to avoid this. There is one possible candidate mentioned on page one. (It was not available to me as no companies would ship it to Alaska.)

 

On page one someone also mentions the rather expensive Tethertools device. But be aware that it has been reported to not work well at freezing temperatures, as the small Li-Ion battery of that device used to buffer power draw will not charge at those temperatures. One would still need an additional battery bank for it.

 

Make note that Nikon's own AC to DC adapter has 9V, not 8V output.

 

I also posted some of this information in this forum:

https://www.cloudyni...0-dc-operation/

and a brief mention here:

https://www.cloudyni...eed-more-power/


Edited by otoien, 02 August 2020 - 12:11 AM.



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