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though it will be (in the case of a lithium primary battery) fully charged, these rules ensure there is a minimal risk of any discharge occurring, except the normal, minuscule and safe levels of leakage current. This is a broad description of the function of the regulations. The detail of the regulations themselves runs to many hundreds of pages. Numerous variations in the requirements for packaging, handling and labelling apply, depending on the type, weight, size and capacity of the battery, the end equipment it is to be carried in (if applicable) and the shipping method. In addition, exceptions apply to low-capacity batteries (<100Wh batteries or <20Wh cells), and to low quantities of batteries, such as prototypes used in pre-production development or testing programmes. So how can an OEM operate with confidence that it is complying with all the relevant regulations, and that it is able to guarantee the safety of its equipment in transit? Clearly these questions are of the highest importance to commercial manufacturers: the cost of liability in the event of proven negligence, and the risk to a manufacturer’s brand, are incalculable. However small the risk, it must be eliminated. Proven transportation techniques Fortunately, experience is on the manufacturer’s side. General industry experience shows Fig. 2: UL and other internationally-recognised standards provide for the verification of a lithium-ion battery’s quality that implementation of the IATA and ICAO regulations has achieved its aim: the number of safety incidents reported in the air or on the ground attributable to lithium batteries since the current rules were put in place has fallen dramatically. The particular experience of reputable battery manufacturers such as VARTA Microbattery is also helpful. The company itself continually ships batteries by air and by other modes of transport, and so has great experience of the procedures for complying with the DGR. OEM customers can draw on this experience: VARTA Microbattery, for instance, is often asked by customers to provide advice on whether new packaging complies with the DGR. Beyond these general points, however, there are two general practices that OEMs should follow in order to ensure they comply with the DGR, and eliminate their liability to the risk of unsafe transportation of lithium batteries. Take a keen interest in your cell and battery supplier’s products, quality procedures and quality standards. As described above, defective cell-production processes can give rise to a risk of short circuits. A reputable battery pack manufacturer will also ensure that the pack is protected by a multi-level protection scheme, which will include software-controlled over-current, over-temperature, over-voltage and under-voltage shut-down mechanisms, as well as an active and a passive fuse for hardware over-current shut-down protection. These mechanisms guarantee the safe operation of the battery in transit, even if it is activated. (The packaging design will normally prevent activation.) It is clear, however, that a risk arises from the use by consumers of replacement ‘counterfeit’ batteries not supplied by the original manufacturer. These cheap batteries mimic the form factor of the original, but often lack adequate fail-safe protection mechanisms to ensure safe transportation and operation. The DGR applies to batteries carried on-board by passengers as well as to cargo shipped by manufacturers. It is an interesting challenge for airlines to devise a method to enforce compliance with the DGR by their own passengers. This risk, of course, does not apply to OEMs transporting batteries in their own equipment. Battery manufacturers can, however, implement authentication technology which renders consumers’ use of counterfeit batteries impossible. Give responsibility for DGR compliance to one person at your company, and give them the power to fulfil their responsibility. The rules governing the transportation of dangerous goods are long, complex and highly detailed. It is not sensible to expect a product, marketing or production manager to know the rules governing the transportation of the equipment they design or manufacture. DGR compliance is a specialised responsibility in its own right. No reputable manufacturer will wish to flout the rules. And in fact one of the most common ways in which manufacturers inadvertently fail to comply with the DGR is when they fail to realise that the product they are shipping even contains dangerous goods! So the first responsibility of the staff member in charge of DGR compliance is to perform an audit of the equipment that the company ships. Any product that contains a lithium cell or lithium battery – no matter how small – must be subject to the company’s DGR compliance programme, even if implementation of the programme reveals it to be exempt from some requirements of the DGR. In short, the regulations for the transportation of lithium batteries are well designed, and proven to be successful in practice. The three steps required to guarantee safe carriage of lithium batteries are easy to list: use only reputable lithium cell and lithium battery brands; appoint a single staff member with overall responsibility for compliance with the DGR; comply with the DGR, and require your compliance to be verified at executive level in the company. While it is harder to implement these steps than to describe them, a battery supplier such as VARTA Microbattery can help by providing guidance, advice and documentation. OEMs need not be alone in their efforts to comply with the DGR. www.electronics-eetimes.com Electronic Engineering Times Europe June 2014 47


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