Powering a time-lapse camera for an extended period of time

Blognosticator Head

I use a Canon T2i camera and a variety of lenses to make time-lapse movies. From time to time I take thousands of photos, and for that I need a special power supply. The standard battery for the camera is a Canon 1200 mAh battery which usually lasts for at least 1,500 frames.But in January I went out on (of course) the coldest night of the year to photograph the night sky. I was taking star trail images at 26 second exposure every 30 seconds.

I was controlling the camera with an intervalometer that I bought from a vendor on eBay. It was made in China, and shipped from China for about $18, and after I ordered it, it arrived by U.S. Postal Service in two days (I can’t get domestic mail delivered outside my own county that fast).

In the cold dark of January 12 I was running my T2i and my Canon 1ds Mark III, each taking similar star trail photos of the night sky. The T2i worked for several hours, then the battery – suffering from the extreme cold – gave up and the camera stopped taking photos.

My other camera continued to shoot long into the night, and had it not been for a cloud cover that arrived in the early hours, I would have a very successful time-lapse movie of the night sky. In a word, the night photography effort was a bust – mostly. I did get one post-sunset panorama against the distant mountains that is really lovely.

Carrizo Horizon Panorama

This is my just-past-sunset photo taken on the Carrizo Plain of eastern San Luis Obispo County, California. If you click on the image, you can see it at twice this size.

So my efforts at time-lapse were not terribly successful that night. Part of the reason was that I was too cold to make clear decisions, and my hands didn’t work well. It was 16 degrees Fahrenheit that night, and that’s too cold for this California boy.

When I got home the next day and got warmed up, I started working on two solutions to the shooting all night problem. One was that I discovered a way to turn off the control screen of the T2i. On the back of that camera, just below the viewfinder, are two tiny windows covering an IR emitter and an IR sensor. These detect the presence of your face when you put your eye on the viewfinder. By covering those with tape, I can get the camera not to illuminate the LCD screen on the back of the camera at all. This saves a considerable amount of battery power, and also reduces the irritation that one causes to other astronomers when that LCD panel flashes on and off.

The second thing I did was to build a replacement battery that is outside the camera, and which has about three times the power of the internal battery.

I thought about building this myself out of a small block of wood, but then I found exactly what I needed on eBay, again from a Chinese supplier. The product is a 110 volt AC power supply for the Canon T2i (and several other Canon cameras). It included a 110 volt power supply, a battery “cheater,” a cord that sneaks out of the body through a little rubber gasket, and a long wire. Buying the Chinese battery substitute cost me about $18 and it took, again, two days to get here from Hong Kong. I couldn’t have built one for $18.

I didn’t want a power supply for 110 volts AC; I wanted a field capable battery pack that will run far from household current. I cut the wire from the 110 volt adapter, and I put it in e-waste. Then I looked on Amazon for a large 7.2 volt battery to replace the power supply. This turned out to be easy because model airplane and boat hobbyists use batteries like the one I needed. I bought the most powerful model I could find, and I bought a charger, and I spent another $30.

Battery cheater

This is the battery “cheater” which is the same size as an internal battery. The cable winds out of the camera to a Molex connector on the other end, which connects to my large battery pack for the camera.

When this stuff arrived in my mailbox, I soldered the ends of the wire from the camera to a Molex connector provided by the battery manufacturer, and I was in business in a matter of minutes. One caution: most electrical cables have the positive conductor marked with a printed white stripe (on a black cable). The power adapter I bought from China had its wires reversed, so that the striped conductor was negative. I discovered this before I wired it, and put the device into my camera, savong it from having 7.2 volts run backward through it.

NiMH Battery

This is the 7.2 V battery pack for the camera. Made for model airplanes and boats, this powerful battery will run my Canon T2i camera for over 4,000 photos. The Velcro strips are to secure the battery to my tripod.

With a fully charged 7.2 volt battery, I can run the camera now for more than 4,000 frames without the battery dying. And in cold weather I can insulate the battery in a wool wrap inside a nylon carrying bag to protect it from freezing.

Cable emerging

Here the battery power cable exits the camera body through a small rubber door that is provided for the purpose. The wire to the battery is about one meter in length.

Charging takes under an hour, and the whole thing is a great success. I also have rigged a parallel plug so that I can plug two of these 7.2 volt batteries in at the same time, giving me almost 7,000 mAh, which would allow me to shoot for days.

I would need to change memory cards in that circumstance, and I would have to do it quickly. I’ll try that some night while I am out shooting the night sky. I plan to do this at least once in the next month, but I am waiting for the right night when there is no moon, and that happens only once every 28 days.


About Brian Lawler

Brian Lawler is an Emeritus Professor of Graphic Communication at California Polytechnic State University, San Luis Obispo and was a Guest Professor at Hochschule München from September, 2021 to September, 2022. He writes about graphic arts processes and technologies for various industry publications, and on his blog, The Blognosticator.
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13 Responses to Powering a time-lapse camera for an extended period of time

  1. Andrew says:


    Just wondering if you had a link, or any other information, for the battery “cheater” that you used?


    • Brian Lawler says:

      Hi Midwinter,

      I searched eBay just now and found one by typing in “Battery dummy for Canon T2i”. The product ships by mail from China, as mine did. It costs $22 including the 110VAC power supply, cable, and the dummy. I cut the wire between the transformer and the dummy, and attached that wire (carefully!) to my big RC battery. Be sure to get the polarity right, as you can damage the camera by putting power into the body with the wires backward.


  2. Andrew says:

    It turns out that Canon actually makes power adapters with dummy batteries for many of their cameras, which gave me a product number to find a cheaper third party one on ebay. Thanks for you help!

  3. Pavol says:

    Hi Brian,
    Great information in your blog. I have the same problem with powering of my old Canon eos 350D (Canon EOS Digital Rebel XT in US) in night timelapse. But I would like to ask you one question. On battery, there are three pins in my case to power the camera: positive, negative and T-pin. I have no idea what is T pin for. Can I ignore it and easyly interconnect only positive and negative pins with red/black wire from new external battery? Sorry for my english, hope you understand what is my problem and will give me answer.

    • Brian Lawler says:

      Dear Pavol,

      You could test the output pins on the battery with a volt meter. I suspect that the positive and negative are the only two you need to concern yourself with. The other wire may not be used at all, or it might be used by the camera to determine battery condition. In any event, power is all you need. Be very careful to maintain proper polarity of the wires from the new battery into the camera. Reversing polarity could damage the camera.

      With a large external battery you will be able to shoot photos all night.

      Best of luck with this!


      • Pavol says:

        Hi, thanks for reply… my goal was at the beginning to “open” old original canon battery for camera and make a “cheater battery” from it somehow, make some connector inside and connect to big battery pack, therefore I was interested on all pins on battery.
        But today, I have ordered the power supply and will make it the same way as you. Anyway, thank you for idea how to do it.

  4. Vrajesh says:

    Thanks for this. This is just what I needed. Last time I did timelapse of night sky, it lasted only 3 hours with default battery even with LCD tuned off. I didn’t want to stay up til 4 in morning to change the battery so I am going to build this and leave it whole night.

    • Brian Lawler says:

      Hi Vrajesh,

      Thank you for your comment. I am glad that my blog may have helped you with nighttime photography. I can’t remember if I mentioned that I figured out how to stop the Canon T2i LCD panel from coming on after every exposure. I put a tiny piece of black gaffer’s tape over the infrared sensor on the back of the camera, and it thinks your eye is on the viewfinder the whole time!


      • Vrajesh says:


        You can also turn off the display by pressing Disp. button. You might have to press it couple of times as it cycles through different display modes. I also turn off the image review when I am doing night photography in menu so LCD doesn’t turn on after each image.

        I don’t know if you’ve looked into MagicLanten firmware for Canon SLR. I’ve been using it for last 6 months and it has lot of good features for taking night photos such as built in intervelometer, bulb ramping (good for taking sunrise and sunsets), HDR videos, etc.

        Here’s the last timelapse I did at BigSur


  5. Shane says:

    Hi, thanks for the blog post. I’m looking for dummy batteries but they seem to have a round black female plug point attached. Sorry I’m a little lost when it comes to power – what kind of battery pack would plug in to that? The battery packs i found at 7.2V for RC boats seem to have different output plugs?

    E.g., how can you connect this battery: http://www.ebay.ca/itm/NEW-VENOM-7-2v-5000mah-NiMH-BATTERY-UNI-PLUG-TAMIYA-HSP-TRAXXAS-LOSI-RC-/151381408504?pt=AU_Toys_Hobbies_Radio_Controlled_Vehicles&hash=item233f08faf8&_uhb=1

    to this dummy battery: http://www.ebay.ca/itm/Lanparte-Ammunitions-Dummy-Battery-Power-For-LP-E8-Canon-500D-600D-650D-700D-/251630781803?pt=Batteries_Chargers&hash=item3a965d056b&_uhb=1

    Greatly appreciated,

    • Brian Lawler says:

      Hi Shane,

      I bought a “battery cheater” for my Canon T2i that is a 110VAC power supply, a cable, and a plastic insert for the camera body with the cable coming out a tiny door in the body.

      I then bought an RC airplane battery with its own style of Molex connector on the end. I bought a matching Molex connector and soldered that onto the cable coming from the camera. It mates, supplying a seemingly unlimited amount of power to the T2i.

      That same plus connects to the RC model battery charger, so it seems to be universal.


  6. Patrick Sparks says:

    Hey Professor Lawler,

    I read the whole post then realized who it was written by! I’m going to see if I can get this setup going ASAP. I shot my first night-time timelapse a week or so ago, and my camera died after about 4 hours. This seems like a great solution. You can check out my first efforts here: https://www.youtube.com/watch?v=6lk0vOlJqk4

    Thanks for the help as always 🙂


  7. Bryn says:

    I use the a/c adapters for canon (actually third party $25 ones) connected to a car jumpstarter with built in inverter. Heavier than a rc plane battery though.
    If only cameras would allow power over the usb power (sony does but only when the camera is OFF), then we could use those nice and cheap 15000mah usb batteries from ravpower and anker and such .

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