Across many industries, compliance standards have been created so buyers are assured that the products they buy comply with certain conditions that regulate performance, endurance and safety. Such standards are widely adopted across national and international regions. Some standards are developed for specific regions, such as the European Conformity (CE) standard, which allows all those who comply with it to trade or sell their products to customers in the European Union. Other standards, such as vibration and shock testing, test the ruggedness and durability of a product. Manufacturers would do well to meet these standards for their own benefit and that of their customers.
Unlike other industries, ultracapacitor manufacturers are not required to adhere to specific compliance standards or standardized testing. This means that ultracapacitor manufacturers voluntarily test their products and all do so differently. For customers, it’s important that compliance standards be an integral piece of the evaluation and purchasing process. When choosing their supplier, customers should have the ability to compare the features and benefits of various products. The only way they can do this effectively is if manufacturers all conform to the same standards, allowing for equal comparison across suppliers.
Adopting compliance standards means ultracapacitor manufacturers would design and test their products in the same manner and against universal standards. Customers would know they are getting a product that adheres to these standards, and they wouldn’t be required to do their own testing after purchasing a product.
Current state of standards compliance and testing
There are several standards and tests that are commonly followed by ultracapacitor manufacturers now. They are:
- Restriction of hazardous substances directive (RoHS) – This is a European-specific standard that ensures the product is not manufactured with materials restricted by Europe. It restricts the use of six hazardous materials (lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls and polybrominated diphenyl ether) in the manufacturing of electronic and electrical equipment.
- Chinese RoHS – This is a Chinese-specific standard ensuring that none of the six materials listed above are present. Products sold in China should be marked whether they are compliant or non-compliant.
- European Conformity (CE) – The CE mark ensures all products manufactured or sold in the EU comply with all of the European safety standards. There are several product categories that are subject to this standard for both professional-use products and consumer products.
- UL 810A – These standards are developed by UL specifically for ultracapacitor technology. The requirements of this test cover ultracapacitor use in equipment such as electronic products, uninterruptible power supplies, emergency lighting, engine starting, and power equipment.
- International Electrotechnical Commission (IEC) 60068-2-6 – This vibration standard tests the product to determine its sensitivity to vibration it might endure during use in high-vibration applications. It attests to the product’s robustness and ensures it will perform reliably.
- IEC 60068-2-27 and IEC 60068-2-29 – These shock standards for products make certain the product is durable in rugged, high-demand applications and that it can handle sudden applied forces and shocks.
- United States Military Standard (MIL-STD) 202G, Method 203C – This random drop test for electronic and electrical parts drops the cell 750 to 1,000 times, confirming it can handle rough conditions in any application. The test ensures topline performance and structural integrity against application conditions or human mishandling.
How to improve standardized testing
Testing ultracapacitors for each of these standards demonstrates to the customer that the cells are rugged and reliable and that they can be sold in various regions. However, the industry as a whole needs to go beyond the above standards and also test against ultracapacitor-specific standards. Outside of the UL testing, none of the above tests are specific to ultracapacitors. Ideally, manufacturers would measure capacitance, equivalent series resistance (ESR), cooling requirements, cycle testing, maximum current, and duty cycles. These are measurements that relate directly to an ultracapacitor’s performance and are most important to customers.
The specifications that manufacturers test for now vary slightly from one to another, and each manufacturer develops its own methods for testing, based on a mix of various specifications. For customers, this can be frustrating, as different products cannot be analyzed comparatively straight across the board. Creating specific, international standards explicitly for ultracapacitors means customers would be presented with data sheets that clearly state test results and they wouldn’t need to run their own product tests, which is in obvious favor to the customer. Standardized testing makes it easier for the market to adapt new products, which benefits the manufacturer. Manufacturers can more easily describe their products’ benefits and how they differ from competitive offerings.
Specific needs for different industries
Each industry uses energy storage devices in different capacities and requirements vary. For instance, an automotive manufacturer will require a much heavier current density than a flashlight manufacturer designing an ultracapacitor into a LED light. When purchasing ultracapacitor technology, automotive manufacturers want to be certain the ultracapacitor will perform reliably under the rugged conditions and wide ranging temperatures present under the hood of a car. Automotive companies have several standards for batteries, such as SAE J2390 for vibration, and as ultracapacitor adoption grows, they will also require ultracapacitors meet certain standards, but currently these customers request that the ultracapacitor perform to battery specifications.
In wind turbine applications, durable ultracapacitors are needed to withstand the high number of revolutions of the turbine over many years. Standardized testing is one way to prove the durability of an ultracapacitor, but only if the manufacturer voluntarily tests its products against these standards. Ultracapacitor manufacturers looking to sell products to turbine manufacturers should perform rotational testing, as well as several other specified tests.
Now is the time for various agencies, such as the National Institute of Standards and Technology (NIST) and the Institute of Electrical and Electronics Engineers (IEEE) to establish standardized testing and compliance that will cover multiple industries or end-uses. Doing so will benefit both customers and manufacturers.=
Chad Hall (email@example.com) is founder and a vice president of sales at Ioxus, Inc., focusing on European sales. Previously, he spent 14 years with Ioxus’ parent company, Custom Electronics, Inc. (CEI). His extensive mechanical engineering and business experience helped establish Ioxus from funding to factory to launch.