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VIDEO
CAMERAS
To determine how long a battery will power
a video camera use this formula: Run Time (in hours) = Battery's
energy rating (watt-hours) / camera's power requirement (watts)
The camera's power requirement can usually be found in the specifications
section of the owner's manual.
Example:
To find how long a Canon XL-1 camera will
operate on an Expedition Battery®: From the "Compatibility
Chart" at www.automatedmedia.com we determine that the Canon
XL-1 camera uses Automated Media Systems' Li-77 battery that has
a 60 watt-hour rating. From the same table or the owner's manual,
specification section, we find that the camera's power requirement
is 7 watts.
Run Time (in hours) = 60 watt-hour / 7 watts
Thus one can estimate 8.5 hours of operating time
Note: Take into account that video cameras consume energy
whenever powered up, even when simply viewing and composing a shot.
During particularly cold weather (minus 40 degrees F/C and below)
some battery de-rating will need to be allowed for.
FILM
CAMERAS
To determine how many feet (or magazines)
of film can be shot on a battery the following calculations must
be done: Run Time (in hours) = battery's watt-hours / camera's power
requirements.
Example:
Camera type is an Arri SR-2 camera.
Assumptions: 16 mm, 24 fps, AMS Li-125 battery, 13.3 VDC.
From the operation manual you can obtain the power requirement of
the camera. In this case, it's 12 watts at 24 fps
Run Time = battery watt-hours / camera's power requirement.
Run Time = 100 watt-hours / 12 watt
Thus, we estimate 8.3 hours
Feet of film = 8.3 hours X 2160 feet / hour
The amount of film through the camera is equal to 17928 feet / battery
Magazine (400 foot load) = 17928 feet X magazine / 400 feet
The above film footage is equal to 44 magazines
Thus, one AMS Li-125 battery will expose up to 17928 feet of film,
or 44 magazines.
Note: At higher film speeds the camera will require more power.
Also, at temperatures below minus 40 degrees F/C a camera's running
current will be higher.
ELECTRONIC EQUIPMENT
(DAT
recorders, audio mixers, Sat-phones, laptops)
To calculate how much operating time can be obtained from an AMS
battery one first has to obtain the power requirement of the electronic
equipment. The item's power requirement is almost always listed
in the operating manual, in the specification section; or may be
found listed right on the equipment.
Example:
To calculate how many operating hours can
be obtained for an audio mixer.
The manufacturer's operation/specifications manual lists the audio
mixer as requiring 1 watt of power at 12 VDC.
Using an AMS Li-125 battery (100 watt-hour, 13.3 VDC) we perform
the following calculation:
Run Time (in hours) = battery (watt-hours) / equipment's power requirement
Run Time = 100 watt-hours / 1 watt
Thus we obtain 100 hours of operating time
Note: For
devices that transmit, such as Sat phones and communication radios,
transmission almost always consumes more power than reception. Consider
the equipment's application and how it's most likely to be used
when determining battery life.
Also, in extremely cold conditions (minus 40 degrees F/C) the battery
needs to be de-rated and the run time lowered.
QUESTIONS
If you have any questions regarding AMS batteries,
power for cameras, solar power charging units, or questions about
power for remote location production send an E-mail to us. We'll
get back to you with the current solution to your questions.
To E-mail your questions about remote power requirements or to contact
Automated Media Systems, write to: Sales@AutomatedMedia.com
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