High Voltage Battery

High Voltage Battery

High-voltage batteries are used in applications where you need to store and release large amounts of energy, for example, a UPS system. Unlike smaller batteries, like your phone’s, a high-voltage battery can power large systems for a long time. You won’t have to charge it every few hours. – the higher the battery’s voltage, the longer it will power your device.

Batteries, by definition, consist of multiple smaller cells that can produce around 3.7 volts of output each. When these cells are connected in series, you get the combined voltage of all of them, typically amounting between 200 to 400 volts. The exact working principle depends on the type of battery you’re using, as discussed below. 

Components of a High Voltage Battery

High-voltage batteries have multiple components that keep them functional:

1. Battery Cells

The output electricity of high-voltage batteries is generated inside electrolytic battery cells. Batteries are usually classified based on the cells they have, like Lead-Acid or Lithium Ion. 

An electrolytic battery cell typically consists of the following components:

• Electrodes: a cathode and an anode.
• A separator membrane that keeps the electrodes apart while letting ions pass through. 
• An electrolyte fluid that lets ions move between the electrodes.
• A collector that connects electrodes and distributes current evenly across them.
• Terminals that let the battery be connected to the load.

2. The Battery Management System

This electronic system oversees the battery and reports multiple parameters, ensuring that the battery operates efficiently and safely. The functions of BMS include:

• Monitoring: The BMS monitors variables like the voltage, temperature, etc., to ensure that the battery is operating within safe limits. 
• Balancing and Control: As high-voltage batteries consist of multiple cells, the BMS ensures they all go through their charge cycles evenly. It overlooks the individual cells’ and the entire battery’s charging and discharging rate. 
• Safety: The BMS includes safety features like overvoltage and overcurrent protection to protect the device and humans alike.
• Communication: The BMS displays information about the battery’s status and information to help users diagnose problems and optimize performance.

3. The Cooling System

High-voltage batteries generate a lot of heat. So, they’re incorporated with a water or air-based cooling system to avoid overheating problems, inefficiencies, and hazards. 

4. The Inverter

Many applications require alternating current (AC), whereas batteries generate direct current (DC). High-voltage batteries come equipped with inverters that convert DC to AC while managing the energy flow between the battery and its load. 

5. The Enclosure 

All battery components are housed inside an enclosure, which may include safety systems too. It can be made of plastic, metals, composites, or ceramic. 

The Types of High Voltage Batteries

You’ll find many high-voltage batteries on the market, including: 

Lithium Ion Batteries

Li-ion batteries generate current by making lithium ions move between the battery terminals – the anode and cathode. Standard components include the following:

• The negative battery electrode (anode) is often made of graphite.
• The positive battery electrode (cathode) is made of a metal oxide, like lithium cobalt oxide or lithium iron phosphate.
• The electrolyte is a liquid or gel that contains lithium ions. Common ones include LiPF6, LiBF4, and LMO.

These ever-so-popular batteries are lightweight and have a high energy density. They’re also relatively fast to charge, earning their place in mobile phones and Teslas alike.

Lithium Ion Batteries are known for their:

• High power-to-weight ratio
• Good Energy efficiency
• Excellent performance at higher temperatures
• Low self-discharge rate

However, they are pricier than other high-voltage batteries and have a limited life span. There are some safety hazards associated with Li-ion batteries’ thermal runaway too.

Nickel-Metal Hydride Batteries

NiMH batteries involve a chemical reaction that produces hydrogen ions and electrons, which travel toward the electrodes to produce electricity. They are made of the following:

• The anode is a hydrogen-absorbing alloy, like mischmetal or AB5.
• The cathode is a nickel oxyhydroxide material.
• The electrolyte is typically an alkaline solution, like KOH or NaOH.

NiMH high voltage batteries have the distinction of being the first ones used massively in hybrid vehicles. They were later replaced by Lithium-ion, however. 

These high-voltage batteries are characterized by:

• a good energy density, especially as compared to lead acid batteries
• a longer overall lifespan
• relative affordability as compared to Li-ion batteries
• environmental friendliness than many options

Note that their energy density and power-to-weight ratio are lower than Li-ion batteries. They’re also more expensive than options like lead-acid batteries.

Lead-Acid Batteries

These batteries involve a chemical reaction between lead dioxide and lead to produce electricity. Components include:

• The anode is made of porous lead.
• The cathode is made of lead dioxide.
• The electrolyte is a sulfuric acid solution.

Lead-acid batteries are among the oldest high-voltage batteries still commonplace. Some defining characteristics include the following: 

• Low cost
• Ease of recyclability
• Readily available

However, these have a shorter lifespan and require more maintenance. They aren’t environmentally friendly either and contain corrosive substances that can be hazardous if leaked. Lead-acid batteries also have a higher self-discharge rate than other high-voltage batteries. 

High-Voltage Batteries vs. Low-Voltage Batteries 

As the name implies, high-voltage batteries have a greater energy capacity and can power devices for a longer time than low-voltage batteries. Specific differences include the following:

• Voltage: Low-voltage batteries are typically rated 200V or less. For example, cellphone batteries are typically charged at 3.8V. In contrast, high-voltage batteries operate at 200V or higher. 

• Energy Density: High-voltage batteries can store more energy in a given size and weight than low-voltage batteries. 

• Safety: High-voltage batteries store large amounts of energy in a small space. So, they require more sophisticated safety features than low-voltage batteries as they pose a bigger risk. 

• Cost: Generally, the more voltage a battery has, the more it costs. 

• Lifespan: High-voltage batteries typically have a longer lifespan than low-voltage batteries – they have more charge and discharge cycles.

Common Applications of High-Voltage Batteries

Due to the unique characteristics of high-voltage batteries, you’ll find them used with large devices and systems. Common applications include:

• Electric Vehicles: Hybrid and electric models need sufficiently large batteries for higher mileage.

• UPS Systems: Backup power systems need batteries with large capacities.

• Renewable Energy Storage: These require high-voltage batteries to store excess energy generated when winds are faster, or sunlight is intense. 

The Advantages of High-Voltage Batteries

Using high-voltage batteries comes with several advantages, including: 

• Significant Energy Density: You can store more energy in a smaller space with these high-energy-density batteries.

• Longer Shelf Life: High-voltage batteries typically have a more extended lifespan, enhancing their feasibility and decreasing their long-term costs. 

• Faster Charging: The high-voltage batteries in today’s markets charge faster, so you can use them more quickly.

The Limitations of High Voltage Batteries

These batteries come with their fair share of disadvantages, including:

• Cost: Both the manufacturing costs and market prices are high for these batteries, limiting their access, use, and feasibility.

• Damaging to the Environment: From troubles in mining cobalt and lithium to the corrosive substances found in the batteries, high-voltage batteries come with environmental concerns. 

• Safety Concerns: Given their large power capacity, high-voltage batteries pose a significant hazard of fires and explosions. Problems like over-charging, overheating, and short-circuiting can have serious consequences.