Power Consumption by Camera Model
A useful comparison of the power used by each of the different GoPro camera models in various modes which can be used to determine how many hours are available with different batteries, and whether a solar assisted installation is sufficient for long term use. Or if you would be better off with a battery eliminator.
These observations were generated from measurements taken on one camera of each type. That alone, makes them less than scientific. It is to be expected that the cameras will vary from one production lot to another and with different firmware installed. These measurements were made in October 2013 with the current firmware at that time.
|Power Consumption (Watts)|
|Off with TL-003 or PS-003||0.0006||0.0006||0.0009||N/A3||N/A3||0.0014||0.0014|
|Standby2 after 5 minutes||1.2||1.2||0.6||0.6||0.6||0.7||0.6|
|Standby2 after 5 minutes||1.6||1.6||1.6||1.8||2.8||2.3|
The video measurements are averaged over a short time. In fact, the power consumption when shooting video varies greatly with the resolution, frame rate, ProTune setting, action in the video, camera temperature, and lighting. The variation in power consumption and battery life across different video modes is plus or minus 30%.
1. The Hero 2 calculation with WiFi on does not include the power used by the WiFi battery as power was measured at the camera battery terminals.
2. Standby after 5 minutes refers to some models having a mode which automatically drops to a lower power consumption after 5 minutes. This increases the battery life but lets you shoot immediately without having to start the camera.
3. The TL-003 Time Lapse Intervalometer is not compatible with the Silver cameras.
Another comparison of battery life across the Hero 3 models is available on the GoPro Support web site.
Knowing the power consumption in watts allows for a quick calculation of the energy required to operate the camera for a given length of time by multiplying the watts by the time in hours.
GoPro batteries are available in 3.885 Wh (1050 mAh) and 4.37 Wh (1180 mAh). Testing showed that a fully charged new battery can actually supply that amount of power to the camera before it shuts down automatically due to detecting a low battery condition.
A good example to use is a time lapse shoot of one image capture per minute with the Hero 3+ Black edition camera. Standby in photo mode uses 1.9 watts per hour. The 4.37 Wh battery would be expected to last 4.37/1.9 = 2.3 hours. Or 138 shots. The extra power used during the shot itself is minimal.
For comparison, the Hero 3 Black with the 3.885 Wh battery would last 3.885/2.1 = 1.85 hours. 111 shots. Both of these results agree with our tests.
The theoretical calculations must be modified in real world installations. An important consideration is temperature. The battery capacity is affected by both higher and lower temperatures. A winter installation in freezing conditions will dramatically shorten the usable battery power.
If external power is being used to charge the GoPro battery, the efficiency of the charging circuit is also a factor. In order to replenish 4 watt-hours of power, it may be necessary to up to 6 watt-hours of external battery power. If that battery is being charged by a solar panel or an intermittent external power source, it may require 20 watt-hours of solar energy to recharge a 15 watt-hour battery. The exact factor will depend on the battery, the camera model, and the ambient temperature. In all cases, it is best to design your installation for the worst case.
Using the Cam-Do Intervalometer
If the Cam-Do Intervalometer is used, the camera will be off most of the time. If we assume that the camera is turned on once a minute for 10 seconds, the total energy used will be 1/6th as much. The available time for time lapse will be 6 times as long. 13.8 hours for the Hero 3+ Black and 11.3 hours for the Hero 3 Black.The Hero 3 White with the 4.37 Wh battery would be even better with an expected battery life of 4 hours under shooting in GoPro Time Lapse mode and 24 hours using the Cam-Do Intervalometer. An actual test with the smaller battery ran 23 hours and 58 minutes before the first missed shot. After that there were about 20 more randomly spaced shots that depended on whether the camera decided to turn on or not with its low battery. The result is better than expected because the on time was less than 10 seconds.
If the photo resolution is adequate for your needs, the Hero 3 White is the winner for extended battery life in this application.
To squeeze more time out of the battery, shoot less often. Shooting one shot every hour, will result in the battery lasting almost 60 times as long as shooting once a minute.
Using the Programmable Scheduler allows you to shoot only 8 hours out of a 24 hour day, tripling the battery life, if this works for your particular project.
With the external battery, weeks or months are theoretically possible. WE DO NOT RECOMMEND LEAVING THE CAMERA UNCHECKED FOR LONG PERIODS OF TIME. Murphy's Law applies to this situation. You are dealing with a very complex system with numerous failure points, including the camera, the batteries, the SD card, the Cam-Do controller, physical stress due to temperature or other factors, and acts of any passing god or bird. Shit happens. Never install a system without testing it for at least one week where it can be observed and tested. Never leave it unchecked for more than a few days. If the shoot is important, install more than one camera.
External Battery Power
Cam-Do sells two batteries which are useful for extending the battery life, the V15, 15 Wh battery, and the V39, 39 Wh battery. The V60 Wh battery can be used in certain circumstances, but because it lacks the always on mode, it will shut down if there is not a constant drain.
The V15 battery adds 15 Wh to the internal battery energy. The shooting time will be (4.37 + 15)/4.37 = 4.4 times as long. Minus some inefficiency from the camera charging circuitry.The V39 battery adds 39 Wh, multiplying the useful life by about (4.37+39)/4.37 = 10 times. Or 11 times in the case of the older 1050 mAh battery.
The V60 battery was tested with the Hero 3+ Black, shooting video in loop mode with no battery. It lasted just over 24 hours. In theory, it should have lasted 60/2.2 = 27 hours. Video is harder to predict.
For very long shots off grid, the solar panels can provide enough power to shoot for a very long time. In this case, you may need to decide the spacing between shots to maximize the time. Remember that you have to have sufficient battery backup to get through the rainy days as well as sufficient solar power to recharge the batteries on sunny days.
With a 6 watt solar panel you can assume that it will only approach 6 watts output at noon in mid-summer if the panel is perfectly oriented. The rest of the time, the output will be reduced due to the angle of the sun striking the panel, and the extra absorption of energy by the atmosphere as the sun angle is low in the sky. Add to this the number of hours of sun per day that are not obscured by clouds. All of these factors will vary with your location. Just follow these simple calculations.
You can use the excellent Solar Calculator to get an idea of the solar irradiance (solar power available) at your location in order to understand how many watt-hours of energy you are likely to get out of your panel at a given time of year.
Enter your location or a city near you into the Solar Calculator. Use a city at a similar latitude with similar weather, if necessary.
Choose a direction based on your local terrain. If the sun is visible all day, aim the panel due south. If not, aim it for the most sun striking the panel straight on.
Choose the appropriate vertical angle. You should be able to optimize the angle for the time of year you are shooting, so choose "Adjusted throughout the year".
Read the number for the appropriate month. For example, 5 kWh/m2/day in August in Canada. For the 6 watt panel, multiply by 7 to get the Wh per day generated (35 Wh). For the 16.8 watt panel, multiply by 19 to get the Wh per day (95 Wh) generated. The factors are based on the panel size and efficiency.
Testing carried out at two locations in different seasons has shown that the theoretical output is about right for the panel into a resistive load on a sunny day. The theoretical output needs to be scaled back to a real usable output due to cloudy days and inefficiencies in the system charging the batteries. As always, real testing of the actual system in the actual location is necessary.
Cam-Do products are designed for use with GOPRO® products. GOPRO® is a registered trademark of Woodman Labs, Inc. in the United States and other countries.