This article introduces lifepo4 batteries from various aspects, from which you can gain the knowledge you need, such as their categorization, advantages, applications, and so on.

Lifepo4 Battery
Lifepo4 Battery

Contents

LiFePO4 Battery is also called LFP battery; its full name is Lithium Iron Phosphate Battery. Lifepo4 battery is a type of lithium-ion battery. It uses lithium iron phosphate as the positive electrode material, carbon as the negative electrode material, and electrolyte as the medium. It realizes the storage and release of electrical energy through lithium-ion transmission. You may be using the lithium iron phosphate batteries now!

In addition to the positive and negative electrode materials, electrolytes and conductive agents are inside the lifepo4 battery. So, how do they fit together? I believe you are also very curious. Let’s take a look together!

1. Prepare raw materials, including positive and negative electrode materials, electrolytes, separators, etc.

2. Prepare electrode slurry: mix the raw materials and then add solvent to form positive and negative electrode slurries.

3. Prepare electrodes: apply the positive and negative electrode slurries onto copper or aluminum foils, then use rolling, levering, and cutting processes to prepare the electrodes.

4. Prepare electrolyte: dissolve lithium salt in an organic solvent.

5. Assembly: mix positive and negative electrode sheets with separator, then stack them together and assemble them into a battery cell through a series of fixation and packaging processes.

6. Charge and discharge debugging: conduct charge and discharge debugging on assembled battery cells to activate the battery and ensure its performance.

7. Finished product testing: conduct a series of performance tests on finished batteries, such as capacity testing, cycle life testing, safety performance testing, etc.

Strictly controlling every step of the production process is the only way to produce high-quality lifepo4 batteries.

  • Cylindrical Batteries

Cylindrical batteries have a small volume but are widely used, typically in portable devices. They have standard sizes and specifications, with common models including 18650, 26650, 32650, etc.

  • Square Batteries

These types of batteries have a flat rectangular casing and can be combined in series to form larger capacity battery packs. For example, you can combine 4 cells of 3.2v to create a 12.8v battery pack. They are commonly used in electric vehicles, energy storage systems, and other fields, and their size and capacity can be customized according to requirements. 

  • Soft-packaged Batteries

The outer packaging material of soft-pack batteries is usually aluminum plastic film or aluminum polyimide film, and you can custom the outer shape according to different application scenarios. Although soft-pack batteries are small in size and light in weight, their safety is relatively poor and prone to physical damage.

The current rating of lithium iron phosphate battery cells is usually expressed by “C.”

  • 1C

Lithium iron phosphate batteries with a discharge rate of 1C are usually used in the energy storage field.

  • 2C/3C

A higher current allows for better stability and more power for driving, typically used as a power source.

  • Above 5C

These high-current batteries are usually used in the UPS and electric vehicle fields.

Lifepo4 batteries have a wide range of applications, ranging from our daily life, commercial facilities, and industrial equipment to aerospace. For example:

Lifepo4 Battery Application
Lifepo4 Battery Application

Such as electric drills, weed eaters, and high-power electric tools (cordless) you use daily are powered by lithium iron phosphate batteries.

Lifepo4 batteries have the ability to provide instant high-power output, and can be used as starting power sources for electric bicycles, recreational vehicles, golf carts, campers, passenger cars, logistics vehicles, low-speed electric vehicles, and more. These are all common means of transportation.

Lifepo4 batteries have excellent prospects in renewable energy, such as solar energy storage systems, wind power generation systems, and UPS uninterrupted power supply systems. They can store energy during the day for use during peak electricity demand.

Such as remote-controlled cars, planes, boats, and other electric toys, laptops, handheld electronic devices, and more.

Used as energy storage devices, they can improve grid stability; used as backup power sources, they can respond to sudden power demands and grid faults, achieving off-grid operation.

 Electric wheelchairs, electric scooters, and other medical devices.

Include mining lamps, implantable medical devices, replacing lead-acid, nickel-metal hydride, nickel-cadmium, lithium cobalt, and lithium manganese batteries in small electrical appliances.

High energy density and long cycle life make the lifepo4 batteries widely used in military equipment such as drones, military vehicles, and portable electronic devices.

As you can see, lfepo4 batteries are widely used. So, why exactly is that? Let’s look at what makes them so good together, shall we?

1. Good Safety Performance

The chemical properties of lithium iron phosphate are stable and not easily affected by external environments. Even in short-circuiting, overcharging, or compression cases, the battery structure will not change, and there will be no risk of explosion. Compared to other lithium batteries, it has a higher level of safety.

2. Long Cycle Life

Compared to other lithium-ion chemical materials, lithium iron phosphate has a longer cycle life. Especially when applied in the energy storage market, lifepo4 batteries are required to achieve over 4,000-5,000 charge and discharge cycles to guarantee a lifespan of 8-10 years. It has more than 1000 additional cycle life compared to ternary batteries, while lead-acid batteries have a cycle life of only about 300 cycles.

3. Good Working Performance

Lifepo4 batteries maintain a safe and intact structure and operate normally in high and low-temperature environments.

4. Large Capacity

Lifepo4 batteries have a larger capacity than ordinary batteries (such as lead-acid), with single-cell capacities ranging from 5Ah to 1000Ah.

5. No Memory Effect

Lifepo4 batteries support charging at any time without the need to fully discharge them first, and this practice does not affect their capacity.

6. Light Weight

Under equivalent capacity specifications, the volume of lifepo4 batteries is two-thirds that of lead-acid batteries, and the weight is one-third.

7. Environmental Friendly

Lifepo4 batteries do not contain heavy metals or rare metals, are non-toxic, non-polluting, and have a relatively small impact on the environment.

12.8V 170Ah Lifepo4 Battery Advantage
12.8V 170Ah Lifepo4 Battery Advantage

Of course, besides its advantages, it also has some disadvantages that are not as good as expected, but since it can be applied so widely, presumably, you and I can accept these shortcomings.

1. Relatively Low Energy Density

Lifepo4 batteries have a relatively low energy density, meaning the stored energy is relatively small under the same volume or weight.

2. Temperature Sensitive

In low-temperature environments, the discharge performance of lithium iron phosphate batteries will be affected.

3. Relatively High Cost

Compared to other types of lithium-ion batteries, lifepo4 batteries have higher manufacturing costs, low battery production rates, and poor consistency.

4. Strict Charging Requirements

Lifepo4 batteries must be charged under strict control of voltage and temperature conditions to avoid overcharging or over-discharging.

1. Charging And Discharging Balance:

First, ensure that the battery is fully charged.

Next, discharge the battery to a specific voltage or capacity through discharging to ensure the battery is in the same initial state.

2. Cycle Charge And Discharge Test:

Conduct multiple cycle charge and discharge tests on the battery to observe changes in its capacity over time.

Record the current, voltage, and time used for each charge and discharge during the test.

3. Capacity Measurement:

Based on the data obtained from the test, use the following formula to calculate the battery’s capacity:

Capacity (Ah) = ∫(I × dt) / 1,000

Where I is the current (unit: ampere), and dt is the discharge time (unit: hour).

4. Analysis of Results:

Based on the test data and the calculated capacity result, evaluate the performance and health status of the battery.

Charging lifepo4 batteries usually adopts the CCCV charging method, which means constant current, constant voltage. Constant current charging can avoid excessively high initial charging current, which could damage the battery; constant voltage charging prevents overcharging.

You should note the following points during charging:

1. Use a charger compatible with lifepo4 batteries.

2. After checking the charger, plug it into the socket.

3. Connect the charger to the lifepo4 battery, ensuring the correct positive and negative connections.

4. Set the appropriate charging mode and current According to the battery specifications and charger instructions.

5. Begin charging and observe the indicator light to ensure the battery is charging.

6. During the charging process, ensure good ventilation and heat dissipation in the surrounding environment.

7. After charging is complete, promptly unplug the charger to avoid overcharging, which helps extend the battery’s lifespan.

3 Charging Methods- 12V 170Ah Lifepo4 Battery
3 Charging Methods- 12V 170Ah Lifepo4 Battery

Lifepo4 batteries are usually charged using a specially designed charger. We recommend that you use the original charger or a certified charger to ensure the safety and effectiveness of the charging process.

The charging of lifepo4 batteries requires considering multiple factors, such as battery capacity, charging speed, charger power, etc. The specific time needed for charging depends on the specifications and usage instructions of the battery and charger.

When storing lithium iron phosphate batteries for a long time, we suggest that you pay attention to the following points:

1. Temperature

It is best to place the battery in an environment of 0-20 degrees Celsius to avoid it being too high or too low.

2. Dry and Ventilated

The place where the battery is stored should be kept dry and well-ventilated to avoid direct sunlight or rain. A humid environment or being wet by rain may easily cause battery corrosion and decreased insulation resistance, affecting the normal function of the battery.

3. Avoid Impact

When the battery is stored or transported for a long time, professional packaging such as wooden crates, should be used to avoid product damage and leakage caused by battery stacking and compression.

4. For every 3 months of storage, you should recharge the battery to avoid excessive self-discharge due to prolonged storage, which can cause irreversible capacity loss.

Generally, The battery usage instructions will have specific storage guidelines; referring to the instruction manual is recommended.

Installing lifepo4 batteries involves electrical and safety issues, and requires consideration of battery connection, fixation, cooling, and safety isolation. If you are an individual user, it is advised to seek professional installation personnel, and also to follow the manufacturer’s installation instructions.

The repair of lifepo4 batteries requires professional knowledge and tools, preferably handled by professional maintenance personnel or manufacturers. The following are the general steps for battery maintenance:

1. Wear protective gear, equip with a fire extinguisher, take protective measures, and ensure operation in a well-ventilated environment.

2. Evaluate the extent of battery damage. Physically damaged batteries may be irreparable or unsafe to use. There is a higher chance of repair if there are abnormal internal Battery Management System (BMS) issues.

3. Check the voltage.

4. Rebalance the battery.

5. Replace faulty components.

6. Reassemble and test.

Lifepo4 batteries have higher energy density and longer lifespan, but the manufacturing cost of lithium batteries is lower than that of liifepo4 batteries.

The energy density of lifepo4 batteries is higher, and their cycle life is longer. They are also more compact compared to AGM batteries. However, AGM batteries require less maintenance, while lifepo4 batteries require more attention during storage.

Cost: The manufacturing cost of lead-acid batteries is relatively low, but their cycle life is short, usually only about 300-500 cycles.

Energy density: Lifepo4 batteries have a higher energy density, meaning they have a longer service life. At the same capacity, lifepo4 batteries have a smaller volume than lead-acid batteries.

Environmental friendliness: Lifepo4 batteries do not contain heavy metals and have almost no environmental pollution. Lead-acid batteries may cause lead pollution to the environment.

Lithium polymer batteries’ energy density is higher than lifepo4 batteries, and their volume is relatively more minor. They are very suitable for portable devices such as smartphones, tablets, etc.

It is recommended to fully charge lifepo4 batteries, which can give the system enough time to balance them. If not used for a long time, it is recommended to charge to over 50%, and it’s best to charge the battery every 3-6 months.

The complete depletion of the lifepo4 battery may damage the battery’s performance and service life. It is recommended to keep the battery capacity between 20% and 80%, which helps to extend the battery’s service life.

When you choose lifepo4 batteries, you need to pay attention to the following parameters to meet our needs:

  • Battery capacity
  • Rated voltage
  • Maximum charging current
  • Maximum discharge current
  • Cycle life
  • Temperature range
  • Self-discharge rate

Lifepo4 batteries can achieve optimal performance when operating within the normal temperature range. If the temperature is too low, the battery’s capacity and performance will decrease, and irreversible damage to the battery may occur. If the temperature is too high, the battery’s self-discharge rate will increase, leading to accelerated degradation and potentially shortening its lifespan.

The cycle life of lifepo4 batteries is generally around 2000 to 8000 cycles, or even longer, with a service life of 5 to 15 years. The battery life is related to the battery quality, charging algorithm, overall structure, and method you use daily.

As time goes by, batteries will experience a certain degree of degradation. For example, they may suffer from capacity reduction and aging. If the battery is left unused for a long time, it may also lead to imbalance and self-discharge. Proper usage and storage methods can significantly delay degradation and extend the battery’s lifespan.

The chemical properties of lifepo4 batteries are very stable, and their safety performance is much higher than that of other lithium-ion batteries, as they are not prone to explosion and fire easily.

Lifepo4 batteries use non-flammable electrolytes, and their stable chemical composition determines their high level of safety. Therefore, using lithium iron phosphate batteries in your house is also safe.

If your battery exhibits the following conditions, it can be determined to be in an abnormal state:

  • Reduced capacity
  • High self-discharge rate
  • Continuous voltage below the specified range
  • The battery is in a swollen state
  • The battery cannot be charged or discharged quickly
  • The battery temperature is abnormal and is overheating.

A good BMS must have the following protection functions:

  • Overcharge protection
  • Over-discharge protection
  • Overvoltage protection
  • Undervoltage protection
  • Over-current protection
  • Short circuit protection
  • High-temperature protection
  • Low-temperature protection

Connecting batteries in series can increase voltage; connecting batteries in parallel increases current and can store more energy.

Which connection method is better depends on your needs and the application scenario of the batteries.

Although lithium iron phosphate batteries have shortcomings, they have become a gem in renewable energy with multiple advantages. They are also the preferred choice for your house backup power supply.