Stop-start systems are just about standard in Europe, which makes sense considering the price of gas as well as stiff mandates there to reduce CO2 emissions. Stop-start is also quite popular in Japan. In the U.S., it’s stop-start eve, with the feature likely to become widely available in the next year or so. One estimate predicts that more than eight million vehicles in North America will be equipped with stop-start systems by 2017.
That’s good news for folks who get stuck in stop-and-start traffic and it’s also good news for companies that manufacture AGM (Absorbent Glass Mat) batteries. Dr. Paul Cheeseman, vice president of global engineering and research at Exide Technologies, says his firm has produced more than 2.5 million AGM batteries for stop-start-equipped vehicles in Europe.
Cheeseman says the advantages of AGM over conventional flooded lead acid batteries are charge acceptance – the amount of energy available for output – and significantly longer life. “AGM batteries are maintenance-free and last much longer than traditional flooded batteries,” he notes, defining longer life less in months and years than in the amount of work an AGM battery can do.
A typical driver might start their car’s engine four or five times a day, but the engine in a car with stop-start might easily start a dozen or more times on the same travel route. That’s obviously a heavier load on the battery, especially with lights, radio, A/C and whatever else working. By his rough estimate an ordinary flooded battery might last a year or two in a mid-range car with stop-start but nearer six months in Previewa high-end vehicle. An AGM battery would last a lot longer. Exide has been selling them successfully in Europe for the better part of four years. Cheeseman says SureLife™ graphite technology in Exide® Edge™ AGM batteries helps charge acceptance significantly.