Unlike your rugged old NiCad packs, Li-ion batteries begin to age at the moment of manufacture. To assure a long productive life Li-ion battery packs must be properly cared for and exercised regularly. Broadcast facilities that underutilize a camera battery by running it through say less than 25 cycles in a year will see dramatically reduced life and concomitant increased costs for battery replacement.

For most TV facilities about 150 cycles per year is ideal to maintain optimal battery life. For the most commonly used industry batteries this will yield on average about four years of useful service from batteries that retain at least 70% of their original capacity.

Battery construction

For best performance and long life a Li-ion battery’s initial quality and construction are paramount. Most high-quality battery manufacturers like, Anton/Bauer, (or heavy application users like Tesla) utilize the latest generation Panasonic 18650 cells. These cells are small, light in weight, and offer the high energy/high voltage output essential for today’s power-hungry applications.

For broadcasters and shooters, Li-ion’s low self-discharge rate is compelling, a mere 10% of older Nickel Metal Hydride (Ni-MH) or Nickel-Cadmium (Ni-Cd) type batteries. This means that our Li-ion camera batteries retain their charge ten times longer, whether sitting in a camera bag or on a shelf back at the studio. Beyond this, Li-ion batteries do not experience any kind of memory effect – another benefit of the technology.

The importance of smart chargers

To ensure maximum longevity using the proper matching smart charger is imperative. Ideally this means the charger and Li-ion battery must be in constant communication. In many chargers, the state of the battery is continuously monitored, so once a battery reaches 100% the charger effectively shuts down to prevent overheating. 

As the battery discharges over time the charger becomes aware and initiates a small trickle charge to maintain full capacity. In this way the charger monitors temperature, cell voltage, and charging interval; save for this communication, 99% of the time nothing is happening between the battery and the corresponding charger. Suffice it to say the battery will retain maximum capacity and realize its longest life when attached to a charger that understands and can respond to a battery’s present state.

Dangers posed by batteries

The potential dangers of Li-ion batteries are well documented, as recently evidenced in a YouTube video that went viral of a Hoverboard engulfed in flames. In the Hoverboard incident, an inferior manufactured Li-ion battery pack exploded due to the excessive heat from overcharging and insufficient battery protection. Li-ion fires can and have brought down jetliners and destroyed camera rental or television production facilities. Caution must be exercised in the care and maintenance of Li-ion batteries to such overheating.

A battery may discharge in a slow trickle over time or in a moderate controlled way as in the normal running of a camera, or in an instantaneous release of energy that can result in an explosion or fire. Such a fire might be the result of an internal short circuit or the battery could be overcharged or physically damaged. But once a cell goes thermal there is no extinguishing agent that can stop it. As each cell breaks down it fuels the next explosion. Today’s high capacity Li-ion batteries with many cells have an even greater potential for a devastating explosion or fire so proper management of the large battery packs is especially critical.

The best defense against a lithium-ion fire or explosion is investing in high-quality industrial-grade camera batteries in the first place. For instance, Anton Bauer uses the latest generation Panasonic 18 x 65mm cells with several built-in safeguards including a physical 1mm separation between cells so the individual cells don’t touch.

In addition, a metal fuse link CID (Current Interruption Device) placed between the cells is designed to isolate an aging thermally unstable battery that could draw a dangerous amount of energy from adjacent cells and produce a fire hazard. Such features are critical as Li-ion cells constructed of volatile chemicals sandwiched between two electrodes have the potential to spark a fire or explode as the cells age.

Today incidents of battery fires or explosions among users employing high-quality professional camera batteries are virtually non-existent. According to Anton Bauer, not a single one of its Li-ion camera batteries have ever caught fire except in lab tests. According to the company, the batteries are safe because they cannot be over discharged.

The CID associated with each cell is also pressure sensitive so if the heat and pressure rise excessively the CID will pop. Also, if the cell voltage drops below a certain level the battery switches off to prevent more current from being drawn from the battery. If a charger tries to overcharge or over discharge a battery, the battery should protect itself by simply shutting down. Overcharging a battery drives excess voltage into the cells, destroying the inner seals and greatly accelerating the aging process. Good batteries and good cells protect themselves.

Airline battery restrictions

While exploding Hoverboards and cell phones seem far removed from the world of professional broadcast gear, high profile consumer incidents like the Hoverboard fire can have a significant impact on how we operate and conduct our craft. Indeed the Hoverboard debacle seems to have prompted the IATA to implement even more stringent restrictions on the transport of Li-ion batteries in commercial aircraft. 

As of April 1, 2016, Li-ion batteries regardless of capacity or application may not be placed in checked luggage, unless they are attached to the piece of gear for which they are intended. You can put your cell phone, beard trimmer, and Bluetooth earpiece in your checked bag – along with your camera and attached Li-ion battery. This is allowable because the battery is integral to the device.

Spare Li-ion batteries with a capacity of 100wH or less can be carried onboard without restriction but the battery contacts must be taped. Li-ion batteries over 100wH capacity up to 160wH may also be carried aboard but are limited to two batteries per person.

The new rules pertain mostly to the shipping of Li-ion batteries. Li-ion batteries shipped as cargo or in checked luggage cannot now exceed 30% of charge. From a practical perspective this rule seems aimed at cell and battery manufacturers, like Panasonic, Tesla, and others, who ship large quantities of Li-ion cells in single shipments.

Reading between the lines the new transport rules related to the charge state of batteries pertain less to broadcast facilities and end users. Note the IATA rules apply to shipping via commercial aircraft and sea vessels only. The rules do not apply to private or chartered aircraft. In such cases the conditions of carriage are the discretion of the pilot.

NiMH versus Li-ion

Given the transport hassle, safety, and liability concerns of Li-ion, it is not surprising that many broadcast facilities are looking anew at NiMH type batteries. Compared to Li-ion, NiMH has seen few if any advances in technology over the last ten years. This may be due to manufacturers devoting the bulk of their research and development dollars to Li-ion, a technology that lends itself to battery packs that are smaller, and lighter in weight. Li-ion cells are about 1.5x size of a AA battery while NiMH cell is roughly the size of a D cell - for the same draw.

NiMH batteries last just as long as their Li-ion brethren – 2-3 years on average retaining 70% of original capacity. NiMH is also a green technology as opposed to Li-ion, which is chemical-based. This means NiMH batteries may be safely and legally disposed in a common landfill – a potential significant cost savings for broadcasters especially in Europe. In the last few years Anton Bauer reports a marked increased in sales of NiMH type batteries to major news organizations. This trend may well continue as even more restrictive airline rules come into play.