GoPro Battery BacPac

I purchased a GoPro Battery BacPack recently because I realized that I’d rather have extended shooting than have two seperate batteries that needed to be charged. I had already purchased a second standard battery for the GoPro, but I didn’t have a way to charge it when it was not in the camera, so found it less useful than I was hoping.

The fact that I am most often using my GoPro in harsh conditions means that I’d rather not open the case any more frequently than I need to. When I’m skiing, if I go into the lodge to change the battery, the very first thing I notice is that the cold GoPro case is suddenly steamed over by the indoor humidity. 

When I’ve been doing my stop motion photography at a picture every two seconds, generally the standard battery lasts just under two hours. My first test with the BacPac attached started at 8:47am and the last picture was at 12:40, so it looks like It gets me to just under 4 hours total.

It created 6999 files in that time frame. I’ve not figured out if the GoPro uses any less battery when taking sequential still photos vs when it’s taking movies. 

Saturday’s race on Different Drummer wasn’t fully captured in the time allotted because we went out early and did some practice work flying the spinnaker.

Hopefully I’ll get around to writing more about what comes with the BacPac in the next couple of days. I was mostly interested in sharing the extension of the recording time.

Time Lapse Videos using FFMPEG

I’ve been creating time lapse videos using FFMPEG from the output of a GoPro camera since the beginning of summer. I have always been interested in the output but not had easy methods of creating them until recently.

I like the result best when I have the GoPro set to take one image every 5 seconds, and then I have FFMPEG create a default MP4 file at 25 frames per second. The standard GoPro battery seems to record just about two hours worth of full resolution images in my Hero 3+ Black, which works out to just about a minute of video.

My first video using this method was of the sunset over Elliott Bay taken through the window of the elevator waiting room where I live, on the 13th floor.

I’ve written a program that copies the default GoPro image file names to a sequence that starts with image number 0000 so that FFMPEG will recognize a starting sequence with the default globbing method.

An example command line I use to start FFMPEG is:

ffmpeg -i \\MyServer\Pictures\GoPro\Sunset2\Wim%04d.JPG \\MyServer\Pictures\GoPro\Sunset2\Sunset2.mp4

That command line will actually create a video that has a resolution of 4000×3000, which is the resolution I’m taking the individual pictures. I could have specified to FFMPEG to reshape the output, or trim it.

The second video I created using this method was of a sunrise in essentially the same location.

https://trac.ffmpeg.org/wiki/Create%20a%20video%20slideshow%20from%20images has good examples of some of the options.

The most recent video was created after I purchased a suction cup mount for my GoPro. I went to the 17th floor and read a book during the hour before sunset.

Several things are apparent in this process.

  • I need a black out curtain surrounding the camera to block reflections when the light is directed at the camera. The camera has been positioned flush against the surface of the glass, but the thickness of the glass creates reflections inside the glass itself.
  • videos with weather are much more interesting than just the movement of the sun itself.
  • I have been turning on the WiFi in the camera to make sure I’ve positioned the camera correctly. I need to try turning off the WiFi to see how it affects the battery rundown length.
  • I need to change the picture frequency to a longer or short time-span to see if the battery life is affected at all.