# Is there really no way to power a DSLR by USB?

I made some scripts on my Raspberry Pi to automate a daily shot at a specific hour.

My DSLR is plugged in through USB. I thought this would keep its battery charged, but no.

Is there really no way automate a DSLR to shoot every 24 hours without having to pick it up, charge/replace its battery, and put in back on the same spot?

• Maybe new DSLRs will be powered by USB. Now some mirrorless cameras can be powered by USB, for example Sony a6300/a6500. But you still have to keep the camera battery inside the camera. – vladiz Feb 7 '17 at 11:49
• v3.2 USB-C has 100w and up to 20v. More than enough for charging, if you can find a camera with this kind of port. – cybernard Jun 8 '18 at 21:43

Is there really no way automate a DSLR to shoot every 24 hours without having to pick it up, charge/replace its battery, and put in back on the same spot ?

Canon and Nikon cameras can be connected to AC power by means of an adapter that fits in the battery slot. For example, Canon DSLRs that take an LB-E6 battery (like the 5D II, 6D, and 7D) can use an ACK-E6 adapter:

And Nikons that take a EN-EL14 battery (like D3200, D5200, etc.) can use this EP-5A AC Adapter:

I've seen similar arrangements for other brands as well. The best plan is to check the list of accessories available for your camera -- there are sure to be solutions for powering your camera both from AC power and also from a 12V vehicle battery.

• There are also cheap equivalents from companies like Hama. I've made my own for an old 350D based on a suitable power supply. – Chris H Apr 17 '16 at 15:59
• The same is true for Pentax DSLR's. Point of caution for cheap equivalents: I found it difficult to find an alternative adapter that has the right pin and the right voltage and that delivers the right power (ampere or watt) according to specifications. After some failed "cheaper" attempts, I ended up with the "official" adapter, which works fine. – agtoever Apr 17 '16 at 18:33
• @agtoever it took me a few tries with a bench supply and decent multimeter to build mine successfully. – Chris H Apr 17 '16 at 21:00

No, cameras can not be powered by a USB port because they typically require more than The 5 volts maximun available from the USB port.

• It would be easy enough for the camera to include some sort of converter, to change the 5V to whatever it needs. It probably has a converter for the voltage from the batteries anyway. – vclaw Apr 17 '16 at 17:34
• It's not just volts - it is amps as well. When you step up the voltage you reduce the amps. – Michael C Apr 17 '16 at 18:45
• Which is to say, it's about power. – JohannesD Apr 17 '16 at 19:40
• A USB-2.0 port can deliver up to 5W according to specification (5V, 1A) which is enough to drive a harddisk or a dvd-burner. Things get much simpler if the host does not have to power the device - you may for instance talk to the camera using your low powered smartphone over USB. – Thorbjørn Ravn Andersen Apr 17 '16 at 20:13
• In my tests, a 350D draws 1.5A at 8V for a brief moment after shooting with the flash. So you'd need significant energy storage for a USB-powered system. (The ammeter reads at 4Hz, exactly one reading per shot was >1A, and I had 1500µF in the battery casing I had modified) (@vclaw et al.) You could of course charge a battery using a voltage converter as many compacts do. Maybe there's a battery grip with charge input. – Chris H Apr 18 '16 at 8:24

Many DSLRs have external power jack (it is often cylindrical, like those which are used in laptops). Some others might use an AC adapter which fits into the battery compartment.

Most DSLRs cannot be powered through their USB port (in fact, I have not seen any that can).

• None of the DSLRs that I have seen had a power jack. What let you arrive at the conclusion that most of them have one? Do you have a source? – null Apr 17 '16 at 16:13
• @null: only one camera from those which my family owns does not have a power jack (and that is a DSLR, BTW). Still, corrected the post. – Euri Pinhollow Apr 17 '16 at 17:01
• Since Nikon and Canon DSLRs don't have jacks for DC power, and Pentax DSLRs apparently don't either, what's the basis for your claim that "many" DSLRs have such a jack? – Caleb Apr 18 '16 at 4:44
• "Since Nikon and Canon DSLRs don't have jacks for DC power, and Pentax DSLRs apparently don't either": 1, 2, 3 (this one is not even a DSLR), 4, 5(not a dslr as well). Never was interested in Canon. – Euri Pinhollow Apr 18 '16 at 6:36
• You see that that question is specific to DSLRs, right? – Caleb Apr 18 '16 at 13:16

Being able to do this over USB is unlikely but not impossible.

My Nikon D750 has 7-9V 2.5A stamped on the bottom of it. That's a draw between 18W and 22W.

This is significant because you can buy USB step-up converters to get to 9V. The problem is most of these (one example) are limited in terms of current output to around ~5W... And 7W before they start to melt.

I'm certain you'd start to get supply issues at the USB end too past a point.

So short of chaining together multiple supplies, this probably isn't going to be an option for a full-on DSLR. It might be an option for a lower-power camera especially if you can disable the screen, etc.

If you can do the timing internally (many DSLRs can) is a battery grip available? I'm not sure how many shots you're planning but in my experience the timer doesn't use that much power. I get weeks of standaby from mine. I could double that with a battery grip. Perhaps more with higher density batteries.

What's killing it for you is being hooked into a USB interface. Assuming you have good standby power usage, an external timer would be a better idea than leaving it on USB indefinitely.

A separate power supply is by far the better option but if you're out of range of an AC supply, a car battery can easily supply currents like 2.5A through a cheap step-down transformer. This one can pump out 8A. 12A if you improve the heatsink.

More than enough to power the camera. Add a 5V supply power supply and you can power the Raspi too.

The great thing about picking a 12V lead-acid supply setup is it's used everywhere and rural demands mean there are solutions for keeping batteries trickle-charged via solar (or mini wind/water turbines, etc). Indefinitely.

The problem now becomes keeping your camera protected. I'm not an electrical engineer (I'm just enthusiastic and well-caffeinated) so it might be ill-advised to stick something like that into your camera without additional smoothing and/or additional voltage regulation.

If you're uncomfortable with this sort of stuff, I'd aim to find a local electrical engineer. The parts cost for something like this (past the battery) really are negligible.

• That 7-9V 2.5A is probably peak power. If it were continuous the camera would get Real Hot and drain the batteries in no time. If the peak is very short (less than 100ms for instance) USB3 may suffice if you provide a large capacitor. It will take the USB power source a bit longer to charge the capacitor again, so you probably can't shoot faster than, say, 1 picture per couple of seconds. – Joris Groosman Feb 6 '17 at 17:16

The simplest way to get the voltage you need from USB is to use a cheap buck up/down (depending on whether you need more or less than 5V) convertor (such as the down convertor based on the MP1584, available for around a pound / dollar / euro) These can be around 80%+ efficient and shift the voltage from the 5V available on the USB port to whatever (within reason) you need. That solves the voltage problem, but what about the current ? Most cameras only need a high current momentarily (when recharging the flash for instance) This can be achieved by adding a capacitor in parallel with the output of the convertor to provide a short duration of extra current. Bear in mind that you may have to add a resistor between the capacitor and convertor to limit the current so as not to overload the output of the convertor when you switch on. (some convertors are safe and don't need this)

I put together a homemade solution using an 8V 1A power supply and a capacitor in the old battery housings. I'd recommend this approach if you're confident in your electronics ability, in particular in your ability to do it all patiently and carefully. You could easily fry the camera if you get it wrong. Access to a bench supply, combined with a camera that's on its last legs, are recommended.

• This is more discussion than answer. Could you turn this into a true answer, without the discussion aspects? – jrista Apr 18 '16 at 17:12
• @jrista I won't write a whole tutorial on a diy solution for an unknown camera I probably don't have access to. The only bit that's probably off-topic is the part about my trigger solution as the OP hasn't asked about the problem it solves. The rest is important to designing your own power adaptor. – Chris H Apr 18 '16 at 18:24
• Seems TFuto did an admirable job eliminating the discussion aspects. Seems good to me now...if you wish to add more useful answer details, feel free, but try to keep the "chattiness" down. – jrista Apr 20 '16 at 6:59
• @jrista in more inclined to delete or at the moment. The useful point about power saving mode kicking in when running over USB is gone, and this is more likely with a homemade solution as I describe. – Chris H Apr 20 '16 at 7:08
• Add that point back in. – jrista Apr 20 '16 at 7:22