Idle load electricity consumption wastes over 150 TWh of electricity each year at a cost of over US$19 billion dollars. These inefficiencies cause over 100 million tonnes of carbon dioxide emissions annually. In 2014, the California Energy Commission (CEC) took an active role in reducing idle load consumption by implementing efficiency regulations that targeted battery charger systems for both consumer and commercial applications. Realizing the benefits of these new efficiency standards, the US Department of Energy (DOE) adopted the CEC consumer standards in 2016. The new DOE standard, with required compliance no later than June 2018, states that large battery charger systems (input power > 2kW) must not exceed a 110% charge-return factor (e.g., 10% overcharge). This requirement presents a challenge to deep-cycle lead–acid batteries that are deployed in the US$1.3 billion motive traction market. Current deep cycle batteries require up to 20% overcharge to provide optimum performance, therefore significant improvements to charging efficiency must made. Together with an industry partner, Hammond has investigated the prospects of using novel positive and negative additives to the active material to increase charge-acceptance. This presentation describes how advanced positive additives have been shown to reduce the overcharge to 110% when the battery is new. Moreover, acceptable cycle-life performance is achieved in abusive undercharging conditions that are typical in applications such as renewable energy storage, golf-cart fleets with energy management systems and defective chargers. The abusive charging environment is simulated with a 105% charge-return cycle test. Under this condition, the battery is able to meet rated capacity and provide 62% greater energy performance. Finally, the additives are a cost-effective solution with less than a 1% increase in battery production cost.
Hammond Group, Inc.
Vice President, Research & Development
Marvin Ho is Vice President of Research & Development at Hammond. He is responsible for the advancement of lead-acid battery electrochemistry through the development of innovative performance additives and lead oxides. He has over 25 years of experience in energy storage technologies such as fuel cells, Ni based and lead-acid battery systems, and has worked with several leading research institutes including IEEES at the Bulgarian Academy of Sciences and Trinity College in Ireland. Marvin has held leadership research positions at Trojan Battery Company and China Storage Battery prior to joining Hammond Group Inc. Marvin earned a PhD in Chemical Engineering from the University of South Carolina. He has published numerous times and currently holds eight patents.