Because of their durability, reliability and long standby time – lead-acid batteries are the benchmark for industrial use. There are several lead-acid battery systems for a wide range of applications from medical technology to telecommunications equipment. Read more about the fascinating technology of lead-acid batteries, their different systems and applications in this guide.
The technology of lead accumulators (lead acid batteries) and it’s secrets
Lead-acid batteries usually consist of an acid-resistant outer skin and two lead plates that are used as electrodes. A sulfuric acid serves as electrolyte.
The first lead-acid battery was developed as early as 1854 by the German physician and physicist Wilhelm Josef Sinsteden. He used two lead plates arranged side by side in a vessel containing diluted sulfuric acid and placed it under voltage. After a few charging and discharging processes, he determined a measurable capacity. However, accumulators were hardly used at that time.
It was not until twenty years later – in 1866 – that the technology achieved its breakthrough. Werner von Siemens developed the electric generator, and from then on the demand for ways to store electrical energy increased. From that point on, it was impossible to imagine industry without the lead battery. Even more than 150 years later, the lead battery is still one of the most important and widely used battery technologies.
General advantages and disadvantages of lead-acid batteries
Lead-acid batteries are known for their long service life. For example, a lead-acid battery used as a storage battery can last between 5 and 15 years, depending on its quality and usage. They are usually inexpensive to purchase. At the same time, they are extremely durable, reliable and do not require much maintenance. These characteristics give the lead-acid battery a very good price-performance ratio.
A weak point of lead batteries, however, is their sensitivity to deep discharge, which could render a battery unusable. Therefore, it should always be charged to at least 20 percent. There are now some models with deep discharge protection. Since smaller amounts of gas are produced during charging, the lead battery must be housed in rooms with good ventilation to avoid explosions.
Lead batteries are generally characterized by a high power density. This means that they can deliver high currents. This is particularly advantageous for industrial use or for starter batteries for vehicles.One of their disadvantages is their relatively low energy density. As a result, they are relatively heavy for their volume. This makes them less than ideal for electric vehicles that need to store a particularly large amount of energy. On the other hand, the high weight can also be put to good use: for example, as a counterweight for machines that have to transport heavy loads.
Different lead-acid battery systems
Lead batteries are now available in different types: lead-gel batteries, lead-fleece batteries and pure lead batteries. The differences are mainly due to the material used as electrolyte. They can be seen, for example, in the possibility of storage, maintenance intensity and performance.
Lead-fleece batteries
Lead-fleece batteries contain acid as electrolyte, which is bound in a micro-glass fleece. An alternative term for this is Absorbent Glass Mat (AGM), which is why it is often referred to as an AGM battery. Thanks to the glass fiber fleece, this battery is leak-proof and maintenance-free. It can therefore also be operated permanently in a lateral position. In addition, it usually lasts longer than flooded variants and offers an improvement in performance and speed.
Lead-fleece batteries belong to the valve regulated lead-acid batteries. With them, it is possible to regulate the amount of hydrogen and oxygen that can escape during charging. Therefore, these batteries are often used where a large amount of energy needs to be stored for a long time, for example, in the emergency power supply. If you use a battery for emergency power supply, emergency lighting, an alarm system or fire alarm system, it must meet the highest quality standards.Due to its many positive properties, the lead-fleece battery is now used in a variety of ways and have different properties:
- Standby lead-fleece batteries are used in UPS and alarm systems. They are designed for few charging processes, but are characterized by a particularly long standby duration.
- Particularly cycle-resistant lead-fleece batteries can be discharged and recharged frequently. The charging process is also faster than with conventional lead batteries. They are used in RVs, marine applications, wheelchairs, medical e-scooters and more.
- Lead-fleece high-current batteries are specifically designed for applications that require high discharge currents in a short time. For example, they can be used in vehicles, motorcycles or robotics.
Lead-gel batteries
Lead-gel batteries use liquid sulfuric acid as the electrolyte, which is bound with silica. This type is also completely sealed and has a valve that prevents the electrolyte from leaking. This makes them easier to transport and they can also be set up in a lateral position. They are also virtually maintenance-free.Since no gas escapes from the sealed design, the batteries can be operated in close proximity to people and in enclosed spaces. In addition, they can be used where higher environmental protection regulations apply, such as on watercraft.
The fields of application are similar to those of the lead-fleece accumulator. Accumulators for cyclic operation are mainly used in electric vehicles, mobile homes, boats or stair lifts. Accumulators designed for continuous operation are suitable for warning and emergency power systems as well as telephone and solar systems.
There is only one thing to be noticed: Since the internal resistance in lead-gel batteries is higher than in open lead batteries, for example, they are less suitable for delivering high currents.
Pure lead batteries
Pure lead batteries are specially designed for particularly demanding applications in industry. They also have a closed design. The electrode is made of high-purity lead, which is thinner than in conventional lead-acid batteries. Alternatively, the plates can be made of a compound of lead and tin. This lowers the internal pressure in the battery, allowing high power density to be achieved in rechargeable batteries. You can find out more about pure lead batteries in this guide.Conclusion
Almost 170 years after the invention of the first lead-acid battery the technology is now firmly established in many different areas of application. Advantages such as long service life, power density and resistance make the accumulators indispensable for industry.
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