TV-BAY June 2013

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Intelligent linking with Steve Emmett Q. What makes a safe Li-Ion Battery? Recently, the Boeing Dreamliner story has added to the perception of the Li-Ion battery as a potentially dangerous item. However, the reality is that Li-Ion batteries are a safe and robust source of portable power, when they are designed and constructed by a recognised battery manufacturer that has specialist battery safety knowledge, and one that is committed to producing high-quality products. The Li-Ion battery construction must be tested by an independent facility in compliance with UN safety regulations, as required by air transport authorities, such as IATA. The battery manufacturer should be able to provide the test reports for your scrutiny. It is a mandatory requirement for Li-Ion batteries to be sealed, in order to preserve the original build standard of the UN certified device, and for this reason Li-Ion batteries should never be opened, let alone resealed. The battery manufacturer is also required, by IATA, to demonstrate that it has a quality management programme in place. The coveted ISO 9001:2008 standard meets these requirements. The mechanical design of the battery must provide protection in the event of accident or abuse, cradling the cells against damaging shock and vibration. However, batteries are likely to be damaged by severe abuse, such as being repeatedly thrown onto the ground. The battery case should be manufactured from high-impact, injection-moulded polycarbonate which is inherently strong (it is used for motorcycle crash helmets), and resistant to battery electrolyte. It is important that the battery pack incorporates high-quality Li-Ion cells from a leading manufacturer. Low- quality cells are susceptible to failure. The Li-Ion cells should be matched to close tolerances so that the battery pack is perfectly balanced. The low- resistance inter-cell nickel strapping and cell layout should be constructed to optimize current sharing, to reduce one of the common causes of cell- imbalance and a shorter battery life. The battery assembly must feature protection systems that control its operating parameters, guarding against: over-current, over-charge, over-discharge, over-temperature, under-temperature and inappropriate charge sources. Multiple levels of protection should be included so that safety is not totally dependent upon the continual operation of a single circuit. To effectively guarantee against shorts that could be caused by electrolyte leakage, the circuit boards should be protected with a vapour deposited conformal coating, such as Parylene; this safety feature is unique to PAG batteries. See Jon Pratchett’s 12 month review of the PAGlink system on p.70 capacities, these can be avoided. PAGlink intelligent linking batteries have individual capacities of 96 watt- hours, which can then be linked to create 192Wh, 288Wh or even 384Wh batteries, providing the high-capacity and longer run-time required. This modular approach is flight-friendly; PAGlink batteries can be taken on- board passenger aircraft, in hand- luggage, without quantity restriction. Li-Ion batteries that have capacities greater than 100 watt-hours are subject to regulations imposed by air transport authorities that limit the number of spare batteries you can take on-board civil aircraft to two, any additional batteries must be ‘installed in equipment’. Batteries that have capacities in excess of 160Wh cannot be carried on at all, but can be checked-in if installed. The PAGlink system allows up to eight batteries, in any state of charge, to be linked for charge or discharge. Combining two batteries also increases the current draw capability from 8A to 12A, which leads us onto another commonly asked question. Q. Why doesn’t PAG make a high-capacity battery? Q. I only need one battery for a days shooting; what are the benefits of linking two? High-capacity Li-Ion batteries have air transport restrictions, but by linking batteries and combining their There are many advantages to be had from linking batteries for discharge. Even if a single 96Wh battery will 46 | TV-BAY MAGAZINE: ISSUE 78 JUNE 2013 TV-BAY078JUN13.indd 46 10/06/2013 15:16