THE SHOP

Performance & Hotrod Business - January '15

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6) Boost or trickle charge again just prior to re-connecting or re-installing into the vehicle. "For vehicles that are in storage most of the time," adds Hellmund, "AGM bat- teries offer the advantage of a slower self- discharge rate. But no matter which bat- tery you choose, the best way to keep a lead-acid battery happy and healthy is to keep it fully charged. This is where a so- called smart charger can pay off in longer battery life." With their built-in electronic manage- ment, lithium-ion batteries can perform some of the functions of a smart charger by themselves. "Our L-series batteries will automati- cally power down after several days of inactivity," says Bennett, "then restart automatically when they sense an electri- cal load. This is a good feature for vehicles that are stored for long periods, because battery maintainers would be unnecessary. Lithium-ion batteries winter quite nicely without intervention or float charging"— and they can be safely stored at tempera- tures between minus-4 and 104 degrees. "Simply fully charge them before stor- age and remove all electrical loads. In the case of our L series, nothing additional needs to be done. With our C and T series, all cables should be disconnected from the battery before long periods of storage." Gaining Traction The tremendous power-to-weight advantage of lithium-ion batteries has made them the overwhelming choice for the new generation of electrically powered vehicles. Might the latest electric vehicle (EV) technology trickle back to starter- light-ignition (SLI) batteries for internal combustion (IC) applications? The ques- tion turns out to be more complicated than it might first appear. SLI batteries, Bennett explains, represent a "distinctive" application with their own unique challenges. "There will be some crossover from EV batteries to 'starter' bat- teries, but in reality there is much to be gained from studying the use of lithium-ion technology in starter applications that could benefit lithium-ion batteries in general." The battery requirements of so-called start/stop or "micro-hybrid" vehicles are also unique, adds Pauken, calling for "higher Partial State of Charge (PSOC) cycling capability, and better charge accep- tance than a standard SLI battery." Also unique are the 12-volt batter- ies carried by production EVs to power accessories. "Since these auxiliary batteries are not used for engine starting, they are designed with different attributes to support their specific application requirements. Developments in both the Micro-Hybrid and EV areas are finding their way into 'starter' batteries as the market prices will allow." AAMP, says Catalano, is developing lithium cells for "EV, hybrid and com- bustion vehicles. Each presents different challenges and needs. But advancements in battery management systems will allow increases in weight efficiency, power out- put and cell life—and with adoption of these technologies, an eventual reduction in cost." And while lead is not a word often asso- ciated with environmental friendliness, Essig points out that lead-acid batteries are "still the most widely recycled. Lead from old batteries is put back into new batteries, keeping the environment safe and helping control cost. And lead-acid batteries also remain the most economi- cal and cost-effective product to provide reliable starting power." "While the lead-acid battery has some disadvantages," adds Hellmund, "includ- ing high weight and low power density; it's economical, works very well at low temperatures, and can be easily recycled. So the future of the lead-acid battery looks bright." "And it's here now," Pauken notes. John F. Katz is a freelance automo- tive journalist and historian. He is a reg- ular contributor to Performance & Hotrod Business as well as other au- tomotive industry publications. He lives and works in south-central Pennsylvania. Just How Smart is A Smart Charger? Sweden-based CTEK bills itself as the builder of "the smartest battery chargers in the world." But what makes a smart charger smart? In short, microprocessor control that enables a CTEK charger to not only charge and maintain a car battery, but to some extent pro- tect and even service it. It's like a battery spa. The moment it is connected, a CTEK smart charger automatically checks for sulfation of the lead plates by measuring the bat- tery's resistance. A very high continuous current will dislodge the lead sulfate, but at the risk of overheat- ing and warping the plates. So CTEK uses high-frequency pulses of current instead, which, according to the company's Matt Ingram, "will mix a lot of that lead-sulfate crystal back into the acid, and drop the rest to the bottom." A CTEK charger also checks for and cor- rects acid stratification. "Multiple periods of deep discharge can leave syrup on the bottom and water on the top," Ingram continues. Again, a very high current can re-mix the acid but risks boiling it off the top, so CTEK uses high voltage—less than the 16-volt limit for most vehicle electronics, but "higher than normal," with reduced current to avoid gassing the battery. To avoid overcharging, after 10 days a CTEK charger cycles into "pulse-mode maintenance, where it shuts off the power to the battery and just monitors its voltage. If the voltage drops, the charger re-charges the battery and repeats the cycle." And, of course, CTEK smart chargers incor- porate surge protectors. "All of those electronics in your car are very, very sensitive," says Ingram. "If you have a con- ventional charger connected, and there happens to be a power surge or a lightning strike, you risk damaging the most expensive computer you own—the one in your vehicle." CTEK offers about a dozen different smart- charger models, including special numbers for 6-volt and lithium-ion applications. The right model for your application is the one that matches the amp-hour rating of your battery. According to Ingram, the new CTEK MUS 4.3 is a good choice for most hot rod and high-perfor- mance applications. Microprocessor control enables a CTEK charger to not only charge and main- tain a car battery, but also to help protect and service it. (Photo courtesy CTEK) January 2015 n Performance & Hotrod Business n 59

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