By John Connell, vice president of Crown Battery’s SLI Products Group
Renewable energy systems are a battery torture test, from extreme temperatures to deep discharges. An unreliable, short-lived battery can leave your company, client or home in the dark (literally).
That’s why you want every battery benefit you can get. Automation in battery manufacturing eliminates many traditional quality variables, and improves battery quality and longevity.
What you can’t see can hurt you
Lead-acid batteries are at the heart of most renewable energy systems. But it’s hard to select them; many battery cases look identical, and brochure specifications rarely tell the whole story.
But walk through a battery company’s plant–or dissect their batteries–and it’s clear why some batteries last longer and perform better.
Some manufacturers use heavier grids and more lead, along with robotic assembly and automated quality control–which benefit end-users but require large investments in R&D, manufacturing, testing equipment and technical expertise.
Other companies still make batteries using outdated techniques and higher-profit materials that compromise performance. Here’s how to tell the difference.
Automation improves key stages of manufacturing
Crown Battery’s field tests and lab studies demonstrate that higher-end materials and automated manufacturing improve battery lifespan. Ask your manufacture whether they use best practices for automation during these key stages of manufacturing.
Paste provides capacity. This mixture of lead oxide and additional materials uses a battery’s wire grid as its support structure. With manual pasting, the paste is only as good as its operator. But computerized pasting does something that’s impossible by conventional means; it instantly measures and adjusts for dozens of variables–outside temperature, paste temperature, oxide reactivity, time in storage, addition rate, flow rate and more. This ensures that active material on plates is more consistent and reliable–for better performance.
The leading cause of battery failure: plates
Plates are key to battery life; they store paste (active material) that allows for chemical reactions. Chemical reactions corrode plates reduce current-carrying ability and can lead to the most common battery failure: internal short-circuiting.
All reputable battery manufacturers use automated grid manufacturing. But many lead-acid batteries are produced using expanded metal and punched techniques–a faster process that, unfortunately, embeds impurities and porosity and lowers performance. Instead, look for gravity-cast grids; their slower, automated assembles floats impurities to the top for removal, resulting in near-zero porosity.
To prolong life, make sure your manufacturer also uses thicker, heavier plates; they better withstand corrosion and hold more paste for chemical reactions.
Separators prevent short-circuiting by electrically insulating positive and negative plates. Better batteries feature both vertical and horizontal glass mat wraps, which add protection and improve rigidity.
Some manufacturers still hand-wrap plates because of the lower initial cost, an imprecise method that increases defect rates and may violate engineers’ specifications. By contrast, automated wrapping machines load plates, brush lugs, cut material to length, wrap the material around plates, and fold it over to engineers’ precise specifications every time. Automation offers additional protection against separator failure, increases lifecycle, and lowers operating costs.
Manual welding only allows for 40 adjustments. But automated Cast-on-Strap (COS) allows for 4,000 adjustments–100 times the precision. COS fluxes battery plates and lugs together instantaneously at a precise temperature–no cold or hot spots, weak points, or incomplete burns. This process eliminates traditional battery failure points including “lead rundown” between plates.
As a result, batteries made using COS offer increased current and lifespan, improved reliability, and lower maintenance and corrosion. (Be sure your battery manufacturer uses cast on strap at all their plants–not just the ones shown in brochures.)
Curing reduces inactive, free lead–which improves battery performance and longevity. This process is traditionally done manually, with hand adjustments from time to time.
Look for batteries made using computer-controlled curing chambers; they ensure that all plates perform their best by optimizing important variables such as temperature and humidity at every stage of the curing cycle.
Precise quality control
Robotic and other automated testing help improve quality control, too. For instance, Crown Battery’s aerospace vision systems inspect parts for defects that human operators could miss–like scanning lugs before COS to ensure proper loading. (Vision systems’ high up-front cost and installation difficulties make them rare in the battery industry; check whether your battery manufacturer uses them.)
Automation can also supplement hand testing for short-circuits, and batteries are heat sealed robotically at leading manufacturing facilities.
Longer life–and beyond
We all know that well-constructed batteries last longer and perform better. But the benefits extend beyond end-of-life to recycling. Because unlike lithium-ion batteries (0 to 60% recyclable by technicians) lead-acid batteries are easily opened and separated/recycled by machine. That’s one of the reasons lead-acid batteries are 99.3% recyclable–more recyclable than an aluminum can.
Together, automated manufacturing steps and quality control can eliminate failure modes and increase battery quality. By improving lifespan, they’re good for the planet–and your wallet.