D800 powered by a V-Mount?

[Brian@202020]

Well I pulled the trigger on the D800 and I would like a power solution to power it with my V-Mount battery system. My V-Mount plate has a D-Tap on the side, so a D-Tap to D800 cable that will change the voltage is what I need. Does anyone have any info on such a cable or solution?

[septndu]

you will need a battery adapter (dummy) from nikon, and rewiring that to some sort of converter to step down the voltage.

the thing i cant figure out is: what is the voltage range this battery/camera can take? 7.4-12v?

any idea?

[eteam]

For a 2-cell Li-Ion battery, 8.4V is roughly the peak charged voltage. 7.4V is a safe voltage for a wall-brick supply.

If you don't have confidence in your knowledge and experience, you can always rig up a Nikon EH-5 AC adapter (through the "dummy" battery adapter).

-- Bob Elkind

[septndu]

thanks for the answer Bob.

the thing about the 'Nikon EH-5 AC adapter' is that it requires AC which wouldnt be too portable.


about the Li-ion battery, doesnt the voltage drops a lot while not in full capacity. will its drop beyond 7.4v and potentially damaged the camera?


i guess what im wondering is. can i use a normal 12v power bank (which usually is about 10v), or if its too high i guess 9v is still much easier to find that 7.4-8v


thanks again

[eteam]

about the Li-ion battery, doesnt the voltage drops a lot while not in full capacity. will its drop beyond 7.4v and potentially damaged the camera?

The nominal operating range for a 2-cell Li-Ion battery is 6.4V to 8.4V.
Chargers should stop charging at 8.4V to avoid over-charging, which damages the cells.
Loads should be disconnected when discharge has reached 6.4V, to avoid deep-discharge, which damages the cells.

In other words, the operating range of 6.4V to 8.4V (for a 2-cell pack) is to protect the batteries from damage, not to protect the load device.

I would not be surprised if the D800 would automatically shut down if the DC supply dipped as low as 6.4V.

i guess what im wondering is. can i use a normal 12v power bank (which usually is about 10v), or if its too high i guess 9v is still much easier to find that 7.4-8v

Because 10V is outside the normal operating range of the D800 power source (the battery), I cannot assume that 10V is safe.

I have never *EVER* heard that there is any such thing as a "normal 12V power bank", or that it is safe to assume that a 12VDC converter is guaranteed to output no more than 10V. No-one is going anywhere near *my* cameras with a 10V supply or a "normal 12V power bank" until I am absolutely convinced that it is 100% safe.

-- Bob Elkind

[septndu]

hello

thank you for explaining.

alright, i guess 10v is pushing the limit.



however, i think i just found a solution that might work for all of us

http://www.xpalpower.us/demos/xp4000...=448&width=728

its is a lithium 4000mah battery with output of 8.4. i assumed its already been regulated down to 8.4v so the output should be quite steady or slightly lower.

(i actually own a different model that says it output 12v and the actual output is 10.1v and another one is 9.9v, i was planning to use it with d800 and that is why i asked)

i guess i will have to buy one more, good thing about this is that it can daisy chain to another battery cause it accept the standard 12v.




can i ask one more question, why do you think the nikon has operating range of 6.4-8.4v. is it because that how lithium battery work, calculate number of cell just like that. can this rule apply to all lithium battery like lithium polymer as describe above? (cause if that the case, the xp4000 is also a 2cell as well?) this will makes it much easier for me to choose a battery in the future.

many thanks
sincerely

[eteam]

alright, i guess 10v is pushing the limit.

Your D800 will thank you.

however, i think i just found a solution that might work for all of us
http://www.xpalpower.us/demos/xp4000...=448&width=728
its is a lithium 4000mah battery with output of 8.4. i assumed its already been regulated down to 8.4v so the output should be quite steady or slightly lower.

It may be regulated to 8.4V output, or it may simply be the unregulated output of the 2-cell Li-Ion battery pack.

(i actually own a different model that says it output 12v and the actual output is 10.1v and another one is 9.9v, i was planning to use it with d800 and that is why i asked)

<Sound of your camera breathing a sigh of relief>

can i ask one more question, why do you think the nikon has operating range of 6.4-8.4v.

You misunderstand me. A single-cell Li-Ion battery has an operating range of 3.2V to 4.2V. This is an attribute of Li-Ion battery cells, just as an attribute of NiMH cells is 1.2V nominal operating voltage. A two-cell Li-Ion battery has an operating range of 6.4V - 8.4V. This voltage range is an attribute of the D800 battery pack, but is not necessarily the range limit of power supplies which can be safely handled by the D800 camera. The D800 camera might very well operate safely beyond this limit, but making such an assumption is not a prudent risk without some affirmative information which supports this assumption.

is it because that how lithium battery work, calculate number of cell just like that.

Yes. For more detailed information, start here and read the 3-part Discover Knowledge tutorial.

can this rule apply to all lithium battery like lithium polymer as describe above?

Generally speaking, you should not make any assumptions about battery characteristics. You should rely on solid information.

In the case of Lithium Polymer cells, its operating range is similar to normal Li-Ion cells.

-- Bob Elkind

[septndu]

wow

thank you so much for your solid knowledge/explanation.

also thanks for the link.

I really appreciated your input.

sincerely

[keylight]

This link might help. It's a hack for taking a Nikon battery (used in D200/D300) and converting it to a dummy for use with external power sources:

http://blurmediaphotography.blogspot...timelapse.html

Process should be similar for D800 I would think.

Good luck!

[septndu]

hey

thanks for the link, its great to see how its work


but for a newer model, nikon already sell one of those dummy battery with wire. i guess all we have to do is find the right voltage power source.



cheers