Power to the People

Powering portable gear used to be really easy. It is again once more.

Powering portable gear used to be really easy. Then it became really complicated with lots of different standards… and now it has become much easier again, courtesy of new technology.

This article explores the battery standards which exist today and why certain cameras, like Alexa 35, work better with 26V; Why 14V batteries work brilliantly with small LED lights but more powerful fixtures need 26V like Aputure 300x/600x.  Finally, the article concludes that lights like Nanlight 900/1200 and even video villages and production sets can be powered by simple portable power stations and how these can work best of all. 

Introduction

In days of old, powering equipment was relatively simple, though batteries weren’t particularly good, so you needed a lot of them but at least you knew where you were!

Location cameras used a single 12V on-camera battery; cameras on dollies were powered by larger block batteries; monitors were powered by 12V dumb blocks; small lights were powered by 12V sources and everything else needed a Generator.  Easy. 

12V battery technology has been around for a long time and those with exceedingly long memories may recall that even the early ARRI 16mm and 35mm cameras (remember the ARRI 16mm SR?!) used these batteries to help them to run in sync at 24 or 25fps.  

The Need for Innovation

The manufacturer’s race to build market share continually improved cameras to feature increasing resolution and higher frame rates. This race resulted in cameras becoming ever more power hungry.  Several manufacturers supplied bespoke batteries that shaped the battery industry and some may be surprised to learn that even the ubiquitous V-Lock battery was initially introduced by Sony for their early professional camcorders. 

Early 12v batteries were very limited in scope and capability, since at the time no electronic capacity gauge was available, so there was always a risk that the batteries could run out mid-shot. 

Dumb blocks used the same lead acid cell technology as those used in cars and which continue to exist today in order to power location monitors. 

Early battery technology was based on lead paste and Nickel Cadmium (NiCad), so both poor for the environment and also bulky to use but from this early technology, whilst the cells were too heavy to use as onboard batteries, custom housings were created to allow camera operators to wear these initially as battery belts, though it wasn’t long before manufacturers introduced their own battery standards. 

So, whilst batteries for many years had been Nickel Cadmium (Ni-Cad), there was a definite  need for better batteries and advancements in chemistry & manufacturing techniques allowed for the creation of lighter, more user friendly batteries that could power the growing market for smaller video cameras.

These cameras were able to use standardised batteries with lower capacity than film cameras and before long, several manufacturers introduced bespoke batteries that shaped the battery industry.  A pivotal moment in this evolution was Sony’s introduction of the V-Lock battery mount which was widely adopted by several manufacturers.  Around this time, the result of a collaboration between cameramen Anton Wilson and his electronic engineer friend George Bauer created another battery system, called the gold-mount, which is still popular and continues to be used by battery manufacturer, Anton Bauer.

PAG created their own custom clip standard too which for a time was really popular in the UK but this has waned in recent years.

The Transition to Smart Technology

A major technological leap was the implementation of the viewfinder fuel gauge which for the first time allowed operators to have real-time battery readouts directly in their viewfinders.

This feature greatly enhanced the efficiency of production workflows, allowing camera crews to make informed decisions about when to change batteries without interrupting the filming process.  This seems so fundamental today but at the time, it was groundbreaking!

Cycle Count and Sustainability

Anton Bauer batteries introduced cycle count technology, allowing rental companies to assess battery usage and share use amongst their fleet, greatly extending the lifespan of on-camera batteries.

Smart compound technologies like Nickel Metal Hydride (NiMH) resulted in lighter batteries with voltage and capacity indicators and enhanced smart chargers improved the way that batteries could be charged and maintained to extend their useful life.

The Technology Transformation means more Battery-powered Accessories

The advent of digital motion picture cameras marked a significant transformation. Solid-state recording eliminated power-hungry mechanical movements, which resulted in lower power consumption whilst at the same time, a shift from Tungsten and HMI to LED lighting technology further reduced the reliance on location generators, which spewed out noxious fumes.

Early LED lights were able to be powered by 12V technology, this meant that they could share the same batteries as cameras used, which made things very easy and this coincided with the widespread introduction of Lithium-Ion batteries which offered smaller, lighter batteries with extended capacities, so before long, the majority of batteries migrated to Li-ion.

A major innovation in the mid 2010s from battery manufacturer, Hawkwoods, saw the battery form factor shrink markedly with the introduction of the Mini V-Lock, which offered the same 98W capacity of a 12V cell but in half the volume and continued to use the same V-Lock standard.  Overnight, this became the battery of choice for crews.

Camera Sensors, Gimbals, and Increased Power Demands

The evolution of camera sensors and the popularity of gimbals led to an increased demand for lightweight batteries. Larger sensors, higher resolutions, and power-hungry 4K; 6K and 8K capture capabilities demanded ever more power from batteries.  Changing production methodology saw wireless video monitoring, electronic distance measurement, wireless lens control, as well as more on-camera accessories became the norm, so production cameras began to resemble a large morass of cables and peripherals. 

Worse, the whole production unit was expected to be powered from the same camera batteries, even though perhaps 3 times more power was now needed and this meant that batteries’ lifetimes reduced markedly and disappointment with poor battery performance becoming a regular gripe with crews.

Manufacturers answered this by creating larger capacity batteries, so the usual 98WH documentary battery was supplemented with the 150WH batteries and larger, though this didn’t change the fundamental issue that 12V batteries were still unable to deliver large loads without sustaining long-term damage. 

Also, around this time, IATA rules which came into force, limited air freight of large Li-Ion batteries, making air transport of larger capacity batteries difficult. Read VMI’s article on 2016 revised IATA Guidelines on air transport of Lithium-ion batteries

Hot-Swap and the Power Law

Higher voltage batteries can deliver more power without stressing the battery cells.

Don’t worry, I’m not going to preach physics at you, but The Power Law is really useful, because it shows us that:

  • 6A at 12V delivers 72W
  • 6A at 24V delivers 144W

So if you consider that most 12V camera batteries (for which the standard has now become 14.4V) can happily deliver 100W of power without stressing the cells, using 2 batteries in parallel instead can double the sustained power output to 200W without damaging the internal chemistry of the cells.

The conclusion of this is that a new hot-swap design, which VMI includes as standard in their kits, allows 2 x 12V batteries to share a common load, so that each battery only works half as hard.  Thus a 150W load shared across 2 x batteries, only draws 75W from each battery. 

So now at last we had an easy and elegant solution which enabled cameras to work for longer durations; batteries were more reliable and crews were happy once again.  That is, until ARRI released the Alexa-35, which was based upon a new 26V connection standard… more on this later.

Lighting – more is more, right?

Whilst early LED lighting fixtures were quite capable of being powered from a 12V battery (think of a 1’x1’ litepanel), it wasn’t long before lighting manufacturers began their own race to make ever more powerful fixtures and more powerful fixtures drew more power.

Aputure, Litepanel, Nanlux and others started to produce lights which required in excess of 100W, and this is when battery powering became complicated.

Batteries Became Complicated!

The early Litepanel 1x1s increased their light output 4 times and then 6 times with the Astra series lights but these were still within the capability of being powered by regular 12V on-camera batteries but it wasn’t long before this limit was reached.

With the introduction of the popular Aputure LS300s, even 2 x regular Mini V-Lock batteries couldn’t provide sufficient power to use these reliably, so Hawkwoods released a high performance 14.4V version of their V-Lock batteries, which they call the High Power V-Locks and these could deliver 15A of output, safely.

[Editors note, for those interested, VMI exchanges the battery clips for the HW HP series plates on the Aputure lighting fixtures (where possible) to maximise the functionality of the HW HP series high current delivery batteries and this minimises arcing risk on the terminals]. 

The Litepanel Gemini 2×1 was one of the first LED lighting fixtures to require 26V native batteries and then others followed, such as the Aputure LS600/600X.  Location monitors became larger too, so whilst 17” monitors were able to run off 12V blocks, as 24” monitors became popular on location, these required more power and 26V was required for battery powering.

A work-around for creating 26V exists by using a dual 14.4V battery clip and by putting these batteries in series, rather than in parallel with the existing hot-swap clips, they output 26V instead, as seen by the Hawkwoods SPG-28 here.

However, this proved to just be a short-term fix, as even more power hungry lights were released, which required 48V battery powering to become the norm.  As a result, the introduction of larger block batteries (like the FX Lion) could provide high capacity (620WH) DC to be able to power them.  Multiple 12V, 26V or 48V outputs proved to be very useful as location batteries for camera, lights or for any other applications.  

However, LEDs continued to become larger and brighter to the point that they were alternatives to large HMI/MSR fixtures.  Today, whilst Nanlux Evoke or Aputure 1200 LEDs draw around 1,200W and none of the batteries mentioned so far were sufficient to power them, we needed another solution.  

Before we come to this though, back to ARRI and the Alexa 35.

ARRI to 26V B-Mount

Faced with the realisation that cameras would continue to require ever more power as the pixel race from 4K to 6K to 8K continued, ARRI designed the Alexa-35. This became the first mainstream digital camera to require native 26V powering.

This meant the design of a new connector, capable of carrying higher current than the historic V-Mount, so a new range of batteries was created. 

Note that a high power V-Lock designed for 26V also exists, called the Gold Mount Plus and is an equivalent alternative to B-Mount.

ARRI in collaboration with BEBOP, designed the (open-source) 26V B-mount battery mount to accommodate the power requirements safely and the new B-mount battery standard was born.

[Editor’s note: B-Mounts incorporate larger contacts than the V-lock predecessor and the battery release switch also completely disarms the battery power. These measures are collectively designed to prevent the camera ports from arcing which can result in a fire hazard.]

The Shift to 240V AC Power Stations

Whereas high-efficiency LEDs necessitated the use of 26V, 28V, and even 48V batteries to power the brightest fixtures, a groundbreaking development in the early 2020s introduced compact 240V AC power stations, which migrated away from the conventional voltage standards incorporating very efficient, microprocessor controlled built-in DC inverters, to facilitate high power 240V AC power..

Think of it as having a mains socket in the field, enabling the powering of video villages and high-power lighting but instead of using a generator, you use a large battery. This marked a significant leap in convenience and efficiency for film and video production crews, as one battery could now deliver up to 3.6KW of sustained power from a single location power station battery.

Whereas none of our conventional batteries were able to supply sufficient power to light an Aputure or Nanlight 1200, a power station battery like an Instagrid One or EcoFlow Delta was now able to power it  for 2-3 hours on full power. Impressive.

Full range of AC Power Stations

You may also be interested to know that some lights (like the Aputure LS300 and LS600s) actually limit their maximum light output when powered by DC, though when powered with a power station battery on AC, they output instead at full power.

Life On Set with a Power Station and Solar Panel

Camera Assistant Louis McCracken shared his experience recently using an Ecoflow Delta Pro battery on a remote set for a Seresto commercial. 

The 3.6KWh battery not only powered two large 17” monitors throughout the shoot but also benefited from a 400W EcoFlow solar panel provided by VMI. Surprisingly, the solar panel not only maintained the battery during use but even charged it on exceptionally sunny days.

[Credit: Louis McCracken]

McCracken emphasized the impressive performance of the setup, stating that there was no need to recharge the batteries in the evenings, thanks to the self-recharging capability during the shoot. Even on less sunny days, the solar panel slowed down the discharge rate, significantly extending the battery life.  In fact, on the second day of the shoot, copious sunshine provided a sufficient boost from the solar panels, that the charge actually was higher at the end of the shoot day, than in the morning!

https://vmi.tv/blog/production-story/solar-panels-boost-video-village/

The Future 

The next generation of “broadcast silent” green battery generators are becoming available with much larger capacities in order to meet demand and based on different technologies and form factors, to suit specific applications, though all avoid diesel and are noise and emissions free (providing they are charged with energy from green sources). 

  • The largest batteries are built into trailer-built units and are based on large battery arrays;
  • Smaller wheelable mega battery power stations offer impressive capacity and outputs.
  • Finally, arrays of smaller AC batteries can work together with smart switching docking technology, to make a larger ‘virtual’ battery.

Here are a few of these to show you a glimpse of things to come.

Trailer-based Power Stations

They are of course suitable for all Outside Broadcast applications and Film Sets, though the challenge will be how to charge them so that they are ready for use the following day and of course, the significant up front capital cost. 

However, as lighting veers away from HMI to more efficient technologies, on-set battery demands may reduce from historic norms, making these new solutions seem more practical and affordable.

Anton Bauer Salt-E-Dog

Videndum have created the Anton Bauer Salt-E-Dog brand have created a monster battery based around climate-friendly Sodium Nitrite chemistry.

Offering 9KWh of capacity and up to 6KW outputs, this giant battery offers multiple DC outputs including 26V, 48V or AC power (up to 6KW) in an easy to wheel device.

The downsides are that it is expensive and weighs an impressive 271kg.

Instagrid DOCK Solution

Instagrid have opted for a more lightweight solution, which they call Hire the Instagrid DOCK to allow up to 3 x 2.1KWh Instagrid AC batteries to be connected and work together to effectively create a single 6.3KWh battery in order to create a new ‘virtual’ 6.3KWh mega AC battery small enough to wheel around on a regular film trolley.  *.

This allows up to 3 x 2.1KWh Instagrid AC batteries to be connected and work together to effectively create a single 6.3KWh battery.

This would create a new ‘virtual’ 6.3KWh mega battery capable of 3.6KW output but which only weighs 65KG, so small enough to wheel around on a regular film trolley.

Best of all, you can swap out empty batteries with full ones whilst in use, meaning that the battery capacity is limited only by the number of charged batteries you have brought to location.
* arriving March/April 2024.

Conclusion

The journey from simple 12V batteries to sophisticated smart compound technologies and open-source 26V B-mounts reflects the constant innovation in the film and video industry.

As cameras evolve with higher resolutions, they also become more power-hungry, so the need for advanced battery solutions becomes crucial. The introduction of Li-ion batteries, smart indicator tools, and cycle count technology has not only improved efficiency on set but also contributed to sustainability too, so there is less need for foul-smelling generators on set.

In summary for camera powering

  •  Use Micro Mini V-Lok batteries for cameras like Sony FX-6, so that you can power peripherals and enjoy long recording times in a very small form-factor.
  • Use 98WH Mini V-Lok batteries for all regular cameras where form factor is a consideration and enjoy flight-safe status for easy air freight.
  • Use the V-Lok hot swap to connect 2 x cells for reduced load and extended record times.
  • Use the 150WH Mini V-Lok for high power drama productions.
  • Use native high power Gimbal batteries, for applications like Ronin-2, which require the full camera kit to be powered from the native gimbal battery. Use B-Bop 26V or Anton Bauer Gold Mount plus for Alexa 35 and other native 26V cameras. 
  • Use NiMH Cine Blocks (e.g Anton Bauer Cine VCLX/Cine VCLX-NM2) for drama dolly-based powering.  – Note that these are also still good for air freight, as they are NiMh based and don’t use Li-Ion chemistry.

In summary for lighting/other applications

Or

Technician innovation continues to shape the industry and influence how filmmakers use ever-improving equipment.  It is exciting to see how an alternative to using smelly, location diesel generators is developing into the mainstream and that sustainability concerns are helping to shape production methods to align with industry demands.

Barry Bassett and Gerard Botha, February 2024.

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