Shooting with Power
Breakdown of Video Camera Batteries including length of use and power consumption
A lot goes into the preparations of any video production. Prior to the day of production, a professional videographer should foresee what he or she will require to be prepared on set, including camcorder(s) and all other accessories. While filmmakers pay a great deal of attention to cameras, sound, and lighting gear, it is just as important to focus on the power requirements necessary to make that equipment function. Some camcorder manufacturers supply an introductory size battery in their handheld cams; a larger-capacity battery solution is a must for all-day shooting. Fortunately, there are hosts of battery/power solution manufacturers that offer ample options for battery sizes and capacities. In some cases, they achieve much more than just powering the camcorder. In order to determine that there is enough power on hand, one needs a general understanding of the power requirements of the camcorder being used, then various battery types, their cell chemistry, and their potentials.
There are two styles of batteries to power camcorders, either mounted to the camcorder, or wearable external power, such as a shoulder pack or waist pack with a power cable to the camcorder. There are three battery cell types that are used to make camcorder batteries. There chemistries are known as nickel-metal hydride (NiMH), lithium-ion, and starved electrolyte (gel cells).
The most popular camcorders, satisfying scores of independent filmmakers and seasoned broadcast shooters today are the 7.2-volt (input power) camcorders. Some examples of these are the Sony DSR-PD170, HVR-Z1/V1, Panasonic AG-DVX100B, AG-HVX-200A, Canon GL-2, XH-A1, XL-2, XL-H1A/S, and JVC GY-HD110U. These camcorders are helping to win many awards at film and video festivals like Sundance, Cannes, and Tribeca, in addition to feeding content to network news agencies.
The range of power consumption from camcorder to camcorder varies. For example, a handheld (7.2 volt rated) camcorder like the Sony HVR-Z1U draws 8.5 watts of power, the Panasonic AG-HVX200A 14 watts of power, and the Canon XH-A1 needs 6.9 watts. And a full-size, shoulder-mounted (12 volt rated) camcorder such as the Sony PDW-F355 draws 34 watts of power, while the Panasonic AG-HPX500 draws 23 watts of power.
In the world of video production people refer to watt-hours, not milliamp hours. It makes it easier to calculate realistic run times of a battery on a camcorder when milliamps or amp hours are translated into watt-hours. This following sample equation illustrates how milliamp hours are translated in to watt-hours.
1. Divide the milliamps (mAh) of your battery by 1000 to find the amp hours.
2. Multiply the amp hours by 7.2 (volts) to arrive at the watt hours.
3. Divide that by the camcorder's power consumption wattage. Amp x Voltage = Watt-Hours
Let's take the large capacity Sony NPF-970 battery with a 6600 mAh rating, as an example:
6.6 amp hours x 7.2 volts of the camcorder = 47.52 watt-hours.
Divide 47.52 by the camcorder's 8-watt capacity for power consumption. The result is 5.94 hours.
Based on the above example, the Sony NPF-970 will provide just under six hours of run time for their 8w camcorder. But the approximation of a battery's run time is subject to many additional factors. Besides the camcorder being left on, many variables will change your run times. Battery performance (drain) is affected by zooming in and out, using the LCD screen, weather, temperature, standard wear of cells in the battery over time of charging, or the implementation of a hot-shoe accessory. Nevertheless, in any productions, being able to calculate watt-hours helps determine how much power one needs to have at hand.
It is worth mentioning that there are very good third party battery manufacturers such as Impact that offer replacement Sony NPF-970 solutions, for example, with their NPF-975. It provides more (7600 mAh) powerful solutions, compared to Sony's 6600mAh
If you would like more a technical overview of video batteries, the professional manufacturer Anton Bauer provides an exceptional video battery overview and guide for videographers to better understand one of the least understood yet most essential elements of a successful video shoot.
Professional manufacturers like Anton Bauer, Bebob, Bescor, IDX, and Switronix Series 7 provide versatile camcorder powering solutions.
Anton Bauer, a battery manufacturer supplying the professional broadcast world for over 35 years, has given shooters the opportunity to virtually shoot a full day with their ElipZ 10k under-camera-mounted lithium-ion battery. It uses high-capacity lithium-ion cells with a 75 watt-hour rating, and can provide run times as great as two to five times those of the manufacturers' OEM batteries that are supplied with the cameras. On a 10-watt camera load, the 10k will run over 7 1/2 hours. An Anton Bauer camera-specific cable joins the ElipZ 10k to your camera's battery plate. In addition to the camcorder, the ElipZ can power the ElightZ 10-watt on-camera fill light, when attached to the camcorder's shoe mount. And to comfortably accommodate hand-held shooting configurations, the EgripZ flexible grip support makes the innovative Elipz10k system a rapidly accepted and a valuable essential powering for the most popular 7.2v pro camera video rigs.
The Series 7 battery system adapts easily to the popular 7.2v handheld DV/HDV/DVCPROHD camcorders by matching a Series 7 camcorder battery adapter plate to specific manufacturers' camcorder battery mounts. This adapter plate has the same footprint, so you can use the Series 7 high-powered lithium-ion battery on a shoot with multiple camcorders. All you need to do is outfit each camcorder with the Series 7 battery adaptor plate specifically designed for it. Add the Series 7's XD-L56S 20-watt LED light atop your camcorder to add smooth, even fill lighting. The XD-L56S can be powered by the Series 7 or by the high-capacity Sony NP-L series batteries as well.
With regard to Sony camcorders with the "L" series battery mount, (NPF-970), Bebob Engineering, draws upon the high-capacity Sony NPF lithium-ion batteries. Their COCO devices are designed to convert the power from a camera's existing NPF battery to simultaneously operate 12V accessories, such as an on-camera light, onboard LCD monitor, or audio receiver. This device incorporates a 7.2 VDC 4pin Hirose connector to power a wireless audio receiver, and a Power Tap connection to provide power to an on-camera light. The COCO-EX1 is a battery adapter for the BP-U60 lithium-ion battery and Sony PMW-EX1. It allows the BP-U60 to power the camcorder, wireless receivers, and equipment utilizing Power Tap connectivity.
In any busy production company, having a hub to charge multiple batteries is a great asset. For the pro 7.2v camcorders by Canon, JVC, Panasonic, and Sony, Dolgin Engineering offers excellent 4-position microprocessor-based battery chargers. Their TC-400, four position series chargers provide fast, safe simultaneous charging, and implement a built-in battery test/discharge module that cycles the lithium-ion pack through charge-discharge-charge and reports true capacity as tested. IDX also makes a quad channel charger for Sony "L" series (NPF),and for Panasonic 7.2v (CGR-D) lithium-ion batteries. Both units offer simultaneous charging and independent battery sensors, and a seven-level charge capacity LCD screen, enabling immediate and easy confirmation of charge status.
Moving forward to address 12- and 14-volt solutions that can be used with the 7.2v camcorders as well as with the larger shoulder-mounted pro cameras, Anton Bauer and Bescor provide connectivity to convert 7.2v to 12v. Depending on the camcorder, they configure their battery solutions to be applied as camera-mounted, shoulder, pouch, or waist packs. If you will be filming all day, you may want to invest in a 12v system. This enables videographers to power their 7.2v camcorders with the long-lasting 12- and 14-volt packs.
Anton Bauer 14v batteries have three studs that mount on their proprietary mounting plate. To attach their battery systems to camcorders like the Sony HVR-Z1U, Panasonic AG-DVX100B and AG-HVX200A, there's a battery plate adapter that fits their 7.2v camcorder battery footprint, and then hard-wires with control circuitry for conversion to their gold mounts. B&H has put together Anton Bauer's 12v pouch kits, like the ANQRPDHDVK for the Sony Z1, and ANQRDVXK for the Panasonic DVX/HVX both provide an impressive 90 watt-hours of operation with their lithium-ion Dionic 90. The Dionic 90 is also configured in an camera-mounted system for camcorders like the ANQRXLHK1 for the Canon XL series, and ANQREX1K1 for the (12v) Sony PMW-EX1.
So you may be thinking: Where are Bescor commercial batteries in the scheme of things? With 25 years of battery making experience, Bescor is known for its reliability, pricing and customer service.
Bescor offers a full range of options in external battery packs for all 12-volt professional cameras. Their nickel metal hydride batteries are made for the higher power consumption of high-end 4-pin XLR cameras. The NMH-54XLR (NiMH) provides lightweight optimal power at a cost-effective price. With a sleek design weighing 22 ounces, it provides 50 watt-hours of power (for example, it will power a 50 watt light for one hour). The NMH-90XLR (NiMH) battery belt version offers 9.5 amp-hours of power (114 watt hours) for 4 to 5 hours of camera usage. It offers the convenience of wearing it on your waist at a weight of only 3.75 lb. Other features include dual outputs (cigarette socket and 4-pin XLR) for versatility and an automatic shut-off charger.
Last, but not least, is the model MM-7XLR (gel cell). A standard in the industry for over 20 years, it offers a small 5.7-lb shoulder pack with a belt loop for wearing on your waist. It is a very affordably priced commercial battery which offers 80 watt-hours of run power. As with all lead acid Bescor battery packs, an automatic shut-off charger is available to maintain battery charging and performance over years.
Your primary battery should be a highest capacity type to provide maximum run time and performance, while a smaller-wattage battery can be used as the back-up spare.
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