Car batteries, not counting those in hybrids or electric cars, haven’t changed much since the introduction of the electric starter. The added strain of more and more electronics has made for incremental yet very slow evolution of the technology. But as more and more mainstream cars are fitted with fuel-saving start-stop technology, the demands placed on batteries are expected to increase exponentially. Start-stop systems, in their current form, will shut down your car’s engine while you’re stopped at a red light and then start it again when you take your foot off the brake pedal. This means the life cycle of the average battery could increase from about 5,000 starts to 50,000 starts easily.
With ever-tighter regulations governing fuel consumption and emissions, this technology will become more and more commonplace, and it would obviously be a lot to ask of our current battery technology to be able to handle this huge increase in use. As WardsAuto reports, battery maker Exide is now working on batteries designed specifically to meet the demands of the new technology. The new battery design is called Advanced Glass Mat, and is an improvement on the traditional flooded lead-acid battery. In a flooded lead-acid battery, a process known as shedding occurs, whereby the positive and negative sides of the battery gradually wear down. With the new design, a polyethylene absorbent glass mat is used between the positive and negative sides. The battery is then also sealed, and the glass mat puts pressure against the positive and negative sides, keeping them apart and preventing wear and tear.
In a flooded lead-acid battery, it usually takes about one minute of driving to recharge a battery after it has been used to start the engine. This takes longer and longer as the battery ages, and this aging would accelerate greatly with a start-stop system, and in as little as a year the recharge time could reach 10 minutes. This would obviously be a problem for start-stop equipped cars, and Exide estimates that most lead-acid batteries on start-stop equipped cars would need replacing after just six months. With the new AGM batteries, aging would be much slower, and batteries would last from three to five years. They are expected to cost about double what regular batteries cost, but this is still much less than the price would be if the technology had necessitated a switch to lithium-ion or some other more exotic material.