Wet cell battery

Types of Wet Cell Battery

A wet cell battery is also called a flooded lead-acid battery. It is by far one of the oldest rechargeable batteries around. Wet cell batteries have liquid electrolytes, and the lead plates in them are porous and absorb the electrolyte solution. There are several types of these wet cell batteries, and they include:

• Flooded Lead-Acid Battery

  This is the most common type of wet cell battery, and it has the electrolyte freely floating. The electrolyte in a flooded lead-acid battery frequently needs to be watered in order for it to last long. They are very strong, very inexpensive, and can be used very easily. They are used in vehicles, backup power systems, and off-grid renewable energy systems.

• Sealed Lead-Acid Battery (AGM and Gel)

  They are also called SLABs. Unlike flooded batteries, sealed lead-acid batteries have their electrolyte absorbed into separators made of fiberglass or into a gelled form of the electrolyte. SLABs thereby reduce the chances of spilling. There are two kinds of sealed lead-acid batteries: absorbed glass mat (AGM) and gel batteries. AGM batteries are more rugged and reserve more cycles of discharge and recharge. Gel batteries have a thicker viscosity of electrolyte and are resistant to high temperatures.

  SLABs are used in uninterruptible power supplies, medical equipment, and telecommunications systems.

Specifications and Maintenance of Wet Cell Battery

Some of the important specifications of wet cell batteries are:

• Capacity

  Battery capacity is the amount of electricity that a battery can store, and it is measured in ampere-hours (Ah). The higher the Ah, the longer the battery can supply energy before it is drained. The needs for energy determine the required capacity. If the systems use a lot of power, then a battery with higher capacity should be gotten. But if it is low power, then a lower capacity will suffice.

• Cycle Life

  Cycle life refers to the number of charge and discharge cycles a battery can endure before its capacity significantly degrades. Lead-acid batteries typically have a cycle life of 1000-1500 cycles. Gel and AGM batteries may offer longer cycle lives (up to 2500 cycles) due to their reduced stratification and corrosion. Longer cycles of life mean that the battery is going to last long. A battery with longer cycles of life will be more suitable for constantly used systems.

• Efficiency

  This is the percentage of stored energy that can be successfully retrieved during discharge. Wet cell batteries tend to have lower efficiency than other types of batteries, generally around 70-80%. AGM batteries have about 85% efficiency, while gel batteries are slightly lower because of their thicker electrolyte.

Maintenance of Wet Cell Battery

The maintenance of wet cell batteries includes the following:

• Watering

  Water or electrolyte needs to be added to the flooded lead-acid batteries regularly. This is to ensure that the plates are always covered with electrolyte. Depleted electrolytes can lead to sulfation and corrosion of the battery plates.

• Equalization Charging

  Equalization charging is a controlled overcharging process that ensures all battery cells are balanced. It prevents some cells from becoming over-sulfated, which can affect their performance. Equalization should be done every few months, depending on usage and battery condition.

• Terminal and Plate Inspection

  The terminals, plates, and connectors should be inspected for signs of corrosion. Corroded connections should be cleaned with a mixture of baking soda and water. It is advised that people wear personal protective equipment (PPE) to avoid exposure to sulfuric acid.

• Hydrometer Usage

  A battery hydrometer should be used to check the state of charge of each cell periodically. This helps to determine the specific gravity of the electrolyte in each cell. It is also used to check the health of the battery by measuring the density of the electrolyte.

Commercial Uses of Wet Cell Battery

Wet cell batteries are used commercially in these places:

• Energy Storage Systems

  Lead-acid batteries are used to store energy gotten from renewable sources, especially solar and wind power. When the energy generation is high, the excess energy is going to charge the batteries. Then when the demand for energy is high and the generation is low, the stored energy will be used to supply energy. Their affordability and reliability make them a good choice for long-term storage within these systems.

• Uninterruptible Power Supplies (UPS)

  During outages or voltage fluctuations, UPS systems support critical equipment like computers, servers, and telecommunications devices with battery power for a limited time. This allows systems to be safely shut down or switched to alternative power sources.

• Emergency Backup Power

  Wet cell batteries are used in hospitals, data centers, and emergency services to power lights, communications, and essential equipment during outages. They provide several minutes or hours of backup power, allowing time for grid restoration.

• Automotive Applications

  Wet cell batteries are used in motor vehicles to support their electrical systems and enable the engines to start. They are also used for supporting infotainment and navigation systems, lights, and other accessories when the engine is off.

• Forklifts and Material Handling Equipment

  Wet cell batteries power electric forklifts and other material handling equipment. Their high capacity and ability to be recharged quickly make them suitable for warehouse operations that require long shifts and heavy lifting.

Features that Affect the Choice of Wet Cell Battery

The features that should be considered when selecting a wet cell battery are:

• Cost

  Wet cell batteries are by far the most inexpensive option among all the different rechargeable battery kinds. Cost is a crucial key determinant, especially where a large number of batteries or large systems are going to be deployed, flooded lead-acid is inherently inexpensive as it is one of the oldest technologies available and it is easy to manufacture. The sealed lead-acid (AGM and gel) come at higher prices due to their advanced construction and low maintenance.

• Temperature

  AGM and gel batteries perform better than flooded lead-acid batteries in extreme temperatures, whether very hot or very cold. Gel batteries are particularly suited for high-temperature environments with a heat-protective additive. AGM batteries are less vulnerable to extreme temperatures, whether hot or cold. Therefore, they are the best choice if the battery storage location is subject to very high heat or extremely cold conditions.

• Charging Speed

  AGM batteries can accept higher charging rates than gel batteries due to their lower internal resistance. This means that AGM batteries can be charged faster than gel batteries, which are generally slower to charge due to their thicker gel electrolyte. AGM batteries work for applications where fast charging is frequently required, like in public transport systems and emergency response vehicles.

• Sizing Options

  AGM batteries also have better space efficiency since they are manufactured in more compact designs. This makes them very easy to use in tight spaces, such as mobile telecom towers and emergency backup systems. Gel batteries are more space-consuming because they contain gelled electrolyte, which takes up more battery spaces.

• Self-discharge Rate

  Gel batteries have lower self-discharge rates, around 3-4% per month, while AGM batteries self-discharge faster, around 5-7% per month. This makes gel batteries ideal for backup applications where long-term storage without discharge is essential.

Q&A

Q1. What are wet cell batteries good for?

A1. Wet cell batteries are good for automotive applications, renewable energy systems, uninterruptible power supplies, industrial equipment, and emergency backup power. Their affordability, durability, and capacity for deep discharge make them suitable for فthese uses.

Q2. How long do wet cell batteries last?

A2. Wet cell batteries last anywhere between 3 to 5 years, depending on use, maintenance, and operating conditions. With optimum maintenance, such as proper watering and equalization for flooded lead-acid batteries, their lifespan can extend up to 5-6 years.

Q3. What maintenance should a wet lead battery receive?

A3. Wet lead batteries should have their water level checked and adjusted regularly, terminal connections cleaned, equalization charging performed to balance cells, and specific gravity measured with a hydrometer to monitor state of charge and health.

Q4. Are wet cell battery chargers different?

A4. Yes, chargers for wet cell batteries, like flooded lead-acid or AGM, have charging profiles that include bulk, absorption, and equalization phases for proper charging. These profiles maintain battery health and prevent overcharging.