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Can I use the battery charger as a direct power source?

I am making an automatic button presser for my Nikon CoolPix 4800 camera so I can make time lapse videos.  My problem is that I don't have a power adapter for my camera.  If I connect the battery charger directly to the battery slot in the camera, will the camera run safely?

There is a jack on the side, but it's a strange jack that I have never seen before.  The jack is listed at 8.4V.

The charger has an output of 8.4V and 600mA

On the bottom of the camera, it says:
8.4V ---- 0.4A
6V -----0.6A

Then, strangely, the rechargable lithium-ion battery says 7.4V, though it could be a typo.

So, if I connect the terminals on the battery charger into the terminals in the camera where the battery hooks up, will it run safely?

Thanks!

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kelseymh6 years ago

Recharging a battery always required a higher reverse voltage than the battery normally supplies. Otherwise, the higher battery voltage will try to push current back through the charger (the "wrong way") and won't be recharged at all.

As for using your charger to supply the camera directly, well, if it is already equipped with a plug that matches the "strange jack", then you're probably fine. That would mean the Nikon folks designed it for this purpose. Have you tried searching either the Web, or Nikon's own Web site, for a power adapter accessory for your camera?

Wehrdo (author)  kelseymh6 years ago
That's the problem, I don't have that special plug, otherwise I wouldn't have any fear of breaking the camera. My plan was to connect the terminals on the battery charger(Picture) directly with wire onto the terminals where the battery connects inside the camera
Battery Charger.png
kelseymh Wehrdo6 years ago
That's probably not the best idea. Because the charger puts out 8.4V, you're relying on the camera's internal voltage regulation to be able to step 8.4V down below 6V (which it's rated to use) without overheating. If you do try it, don't forget that the contacts on a charger are reversed (since the current flows "backward" to recharge the battery) with respect to the contacts for a normal power supply.
Wehrdo (author)  kelseymh6 years ago
The camera must be able to step down the voltage safely, because the power jack calls for 8.4V(Picture). I would feel safer connecting to that jack, but I can barely even see the terminals inside of it. The second picture is the bottom sticker that lists a couple voltage ratings, which I'm not really sure what they stand for. It seems that it will take 6V also, because the manual says the camera will also accept 2CR5 batteries. So, would a 6V adapter work better?
Power Jack Cover.pngBottom Sticker.png
The camera expects the higher voltage AT THE EXTERNAL POWER INPUT, not at the battery terminals -- as Kelsey says, that's for purposes of recharging the battery -- and the circuitry to regulate it down to something acceptable may not tolerate having that voltage presented at the battery terminals.

If you're going to kluge external power via the battery terminals, do not exceed the voltage the batteries would supply. Make sure it's well-regulated, which may not be the case if you're getting it straight out of a wall-wart; again, the camera probably does not have internal regulation on that path and power fluctuations can cause electronics to malfunction in unpredictable and annoying ways.


Wehrdo (author)  orksecurity6 years ago
According to the second review on this page: http://www.amazon.com/Nikon-Adapter-Coolpix-Digital-Cameras/product-reviews/B00062818K/ref=dp_top_cm_cr_acr_txt?ie=UTF8&showViewpoints=1 The adapter does not charge the battery. Wouldn't the camera have to have some sort of power regulator even at the battery input? A battery does not supply constant voltage. As a battery gets lower, there is less voltage. I just tested the battery, and it reads at 7.7V, while it is rated at 7.4V. Like you said, a wall wart isn't regulated. I think that the less load that is on in it, the higher voltage it supplies. I'm not sure if the AC adapter is regulated.
Remember, part of the art of engineering is designing something that will Just Barely work for the expected conditions, thus saving money. If the expected conditions are that the battery doesn't go much above 7.4, I wouldn't bet that applying anything much above 7.4 was safe.
.  The camera may safely accept 8.4V at the battery terminals, but there is a very good chance that kelseymh and orsecurity are right. It appears that the camera will function down to 6V, so I'd try finding a voltage regulator that puts out between 6 and 7.4V (I'd aim for a little over 6).
.  But first I'd try to find the manuals for the camera and see if they give you any info (eg, a schematic or a warning not to use batteries that put out more than 7.4V). Then I'd see if there were any posts about the subject on the Web.
Wehrdo (author)  NachoMahma6 years ago
I can't find any schematics, repair/service manuals, or threads about using a different power source. It seems like a rarely hacked camera. I also don't have a power source that supplies 6.5V or so. Even the wall warts rated at 3.7V test at about 9.7V.
Wehrdo (author)  kelseymh6 years ago
I did some googling, and the adapters are out there to buy, but they're about 20 bucks. Some more googling showed that the batteries are definitely 7.4V, so why does the power-in jack call for 8.4V?