Valve Regulated Lead Acid Battery
Characteristics
There are several differences between valve-regulated lead acid batteries and nonvalve-regulated lead acid batteries. These differences are primarily determined by the materials used for the electrodes. These materials influence the battery’s chemistry, voltage, and charging and discharging characteristics. The electrode geometry is also important, as it affects the battery’s internal series resistance.
Valve-regulated lead acid batteries are designed to reduce or prevent the escape of hydrogen gas, which can be dangerous and potentially damaging to the battery. They also minimize the volume of electrolyte that can change, which can affect the battery’s performance. Unlike flooded lead acid batteries, valve-regulated lead acid batteries are sealed in order to prevent water loss during charging or rapid discharge. In addition, they are less susceptible to gassing and leakage compared to their flooded counterparts.
Another difference between sealed and valve-regulated lead acid batteries is the discharge current. Valves in valve-regulated lead acid batteries are designed to keep the hydrogen gas from escaping when the battery is being discharged. These batteries also utilize lead calcium plates and gelled electrolytes to keep the evolution of hydrogen gas to a minimum.
Among the various lead acid batteries, gelled-electrolyte VRLA batteries have a higher capacity per unit volume. They also have better faradaic efficiency, which makes them more suitable for motive power and photovoltaic applications. These batteries are especially useful for vehicles with high energy requirements and are relatively maintenance-free.
A lead acid battery experiences gradual voltage loss, a result of which the battery’s capacity will valve regulated lead acid battery drop. During this process, lead sulfate crystals form in the electrolyte. If the electrolyte level drops too low, the battery can experience a permanent decrease in capacity. Further, unlike lead electrodes, lead sulfate crystals are not porous, meaning that it’s difficult to convert back to lead.
Lead acid batteries are widely used in vehicles because they offer a lower cost and durability. However, their disadvantages outweigh their advantages. A starter battery, for example, is primarily designed to provide a burst of power, while a deep-cycle battery is designed for continuous power.
Applications
Valve regulated lead acid (VRLA) batteries are a popular choice for automotive applications. They offer superior cranking power, low self discharge, and improved vibration resistance. Developed markets such as the U.S. are seeing significant growth in the valve regulated lead acid market. Two-wheelers are the largest consumer of these batteries. The Indian two-wheeler industry sold 1.42 million units in October 2016.
The global valve regulated lead acid battery market is characterized by a large number of players. Some of the major companies operating in the industry include GS Battery (U.S.A.), Exide Technologies, Panasonic Storage Battery Co., Ltd., and B.B Battery Co., Ltd. Others operating in the market include Fiamm Batteries S.r.l., and MCA Battery Manufacture Co., Ltd.
The valve regulated lead acid battery uses a multi-cell construction with posts and connectors on the outer and inner walls. These cells are connected in series by a thin band of lead (also called a strap) that connects adjacent cells. The eutectic current flows through the metal and plastic straps to form a low-resistance bond between cells.
The valve regulated lead acid battery needs to remain relatively depolarized to facilitate hydrogen evolution and oxygen recombination. This process produces heat, which increases the internal temperature of the battery. This can lead to thermal runaway. Especially if the battery is operated in hot ambient temperatures, it’s a good idea to install a current limiter.
As a valve regulated lead acid battery is a sealed device, it should be charged at a voltage that does not exceed the gassing voltage. For lead-acid batteries, this is typically between 14.2 and 14.7 volts. When it is fully discharged, the battery returns to its nominal state.
The valve regulated lead acid battery has been widely used in various applications. They are commonly used in light electric scooters and UPSs. In addition, they are widely used in portable electric devices. Nickel-cadmium (Ni-Cd) and nickel-metal hydride (Ni-MH) cells have also been used. These batteries are often equipped with protection circuits and valve regulated lead acid battery technology.
These batteries have a relatively high internal resistance. This means that they are susceptible to excessive charging, which reduces the life of the battery. This is why regular full charging of lead-acid batteries is important. This prevents the battery from sulfation and helps prolong its lifespan.
Design
The lead-acid battery is one of the most common energy storage devices. It has been widely used in large-scale applications for decades. In recent years, a new type of lead-acid battery has emerged: the valve-regulated lead acid battery. This battery uses a valve that controls the flow of electrolyte through the cell, which is a gel-like substance that binds the negative and positive plates of the cell. The electrolyte creates a chemical reaction that releases energy and maintains a balanced electrolyte solution in the cell. Its construction is also simple and requires little maintenance.
The valve-regulated lead-acid design is used in advanced batteries, such as those used for standby applications. The valve-regulated design prevents overcharge and discharging, and is virtually spill-proof. It also has a high level of resistance to shock and temperature changes.
The valve-regulated design of lead-acid batteries also helps extend the life of the battery. Compared to flooded batteries, the valve regulated lead acid battery valve-regulated lead-acid batteries are better at cycling over a long period of time. This type of battery also has a higher capacity than conventional flooded batteries.
The electrochemical design of the cell is essential for long-term performance. While thinner plates may result in better performance, they may also reduce the service life of the cell. Other important aspects of valves include the pillar seals, which can be made of thermosetting resins or rubber sealing rings. Finally, the lid to case seal is typically made of thermosetting resin. The valves themselves can be very complex arrangements with flame filters to prevent external ignition of hydrogen.
While lead-acid batteries have been in use for decades, there are many newer, safer designs for portable electronic devices. These batteries require a three-stage charging process to fully recharge. A higher charging current causes electrolysis, resulting in the decomposition of water into gases. A recharge source must be capable of providing the design C-rate bulk stage current.
Lifecycle
The Lifecycle of Valve-Regulated Lead Acid Batteries is a term that refers to the lifecycle of lead acid batteries. It reflects the degradation of a battery over its lifetime. The amount of time required for a VRLA battery to reach its optimum capacity depends on several factors. One of them is the charging frequency.
The valve-regulated lead acid battery market is segmented by application. The automotive industry dominates this market due to its high growth rate. However, the renewable energy sector is expected to grow substantially during the forecast period. This is because of the increase in the use of renewable energy such as wind and solar energy.
In terms of application, VRLA batteries fall into two broad categories: AGM and Gelled Electrolyte. AGM is the most common type of valve-regulated lead acid battery and is widely used in motorcycles and ATVs. Deep-cycle AGMs are used in large-scale amateur robotics projects and off-grid solar power installations. Gel batteries, on the other hand, are expected to grow significantly during the forecast period. These batteries are mostly used in electric wheelchairs, recreational vehicles, generators, and some other applications.
The lifecycle of valve-regulated lead acid batteries is different from that of other lead acid batteries. Unlike lead acid batteries, the VRLA type contains a small amount of electrolyte that gets absorbed in a plate separator. This electrolyte develops into a gel-like consistency and balances the positive and negative plates. A relief valve is also present in these batteries.
The Lifecycle of VRLA batteries is typically three to five years. This is much shorter than the lifecycle of flooded batteries. The lifecycle of a VRLA battery depends on several factors. Firstly, the fully-discharged time and voltage curve is correlated with the usable capacity, which is the key indicator for predicting usable capacity.
Deep-cycle flooded lead acid batteries are the most common type in use today. They come in flat plate and tubular plate designs. While both are similar, engineers argue that the term “sealed” refers to a falsehood since no rechargeable battery can be totally sealed. Both are designed to maintain a low over-voltage potential, which minimizes gassing and water depletion. Despite its low self-discharge rate, the SLA and VRLA batteries are designed to operate with low over-voltage potential to avoid gassing and over-charging.