Expert Guide on Lithium Iron Phosphate Batteries

Buying LiFePo4 Batteries? With so many good quality lithium iron phosphate batteries available in the market, such as Maxworld Power, it is difficult for customers to make a purchasing decision. Read on to find out the key points to consider before putting your hard-earned cash in a lithium battery bank.

Nowadays, the most easy and efficient way to store electricity is to use lithium iron phosphate batteries.

Electricity storage has long been a scientific and technological problem.

Let’s take a look at the qualities of an ideal LFP battery: light, compact, powerful, durable, fast charge/discharge, versatile and safe.

In all of the above categories, lithium iron phosphate batteries perform admirably. They are the smartest choice for a wide range of applications from solar system to long-range electric vehicles.

In this article, you will learn about lithium iron phosphate batteries (LiFePO4), also known as LFP batteries.

You will also learn how LFP batteries work and their main benefits.

There are some always asked questions about lithium iron phosphate batteries?

All in all, the reason why lithium batteries are expensive will be explored with you, and you’ll learn how to make a profit from LFP batteries.

Do you know what a lithium iron phosphate battery is

LiFePO4 battery is a reversible power storage system and one of its components is LiFePO4. When connected to a power source, it can be charged (stored) with energy and discharged (discharged) when an electrical load is applied.

LiFePo4 batteries primarily compete with lead-acid AGM and GEL batteries, but they outperform them in every category, including energy and power density, capacity, and lifetime.

LiFePo4 batteries (direct current) only provide and accept direct current. A single LFP cell consists of multiple 3.2V prismatic LiFePo4 cells.

The 12V LiFePo4 battery consists of four square cells connected in series. Eight prismatic cells were assembled from 24V LiFePo4 cells.

How does lithium iron phosphate batteries work

According to science, LiFePO4 batteries are reversible electrochemical storage technologies. In other words, they used a reversible process to convert electricity into charged electrochemical particles called ions.

Let’s take a closer look at LiFePO4 batteries.

It consists of the following eight key parts:

The only difference between Li-ion batteries (LiCoO2, LiMn2O4, NMC, etc.) is the lithium oxide at the cathode.

And now, let’s get a closer look at the charging and discharging of the battery.

Charging

Lithium ions (Li+) run out from the cathode and transit via the electrolyte to the anode while the battery is charging. Please note the anode has more lithium than the cathode after a full charged.

Discharging

When a power load is used, the reaction of the battery is reversed. The anode transports lithium ions to the cathode so that stores more lithium than the anode after discharge..

At the end, the transportation of lithium ions within the battery causes electrons to flow between the two electrodes, which cause a charge outside the battery.

If you are interested in learning more about the electrochemical equations and materials science behind LiFePo4 batteries, we recommend this free paper, which provides a good overview.

Is Lithium Ion the same as LiFePO4

LiFePO4 is actually a lithium-ion battery.

Lithium-ion is a general term that refers to a specific type of lithium-based battery. You can found the electrochemical performance of Li+ in all lithium-ion batteries.They differ only in the substance used in the electrodes, all of which are lithium oxides (LiCoO2, LiMn2O4 and LiFePo4).

Therefore, LiFePO4 is one of the various types of Li-ion batteries available. Other Li-ion battery types are LiCoO2 – LCO LiNiMnCoO2, NMC LiNiCoAlO2 and NCA LiNiCoAlO2.

To identify the best lithium-ion batteries, chemists and materials scientists are creating many versions of lithium oxide. Their most important discovery to date was LiFePo4, developed in 1996.

Made of lithium manganese cobalt oxide, NMC batteries are the second most popular lithium-ion battery. It has higher energy density (better storage capacity) and power than LiFePo4. It can also handle thousands of cycles and accept fast charge/discharge. On the downside, it’s less safe and more expensive than LFP batteries.

In the field of electric vehicles, NMC lithium-ion batteries and NCA (nickel cobalt aluminum oxide) batteries are commonly used.

Why lithium iron phosphate batteries are cost so much

As everyone knows, LiFePO4 batteries are very expensive, but really?

We cannot rely only on the purchase price (upfront cost) of the battery for energy storage. The total amount of energy (in kWh) that a battery can store and release (charge/discharge cycles) during its lifetime must be considered. Then divide the prepaid fee by this value.

It is interesting when comparing different energy storage devices. Manufacturers now offer extended warranties on many batteries.

Average storage cost for a 24V LiFePo4 battery

Let’s see how much a 100Ah, 24V Li-ion battery costs in terms of levelized cost of storage (LCOS). The current purchase price this battery is $600 with a 5-year warranty. Assuming one full charge/discharge cycle per day, the total capacity is 2.4 kWh.

You will store and discharge a total of 8,760 kWh of electricity over ten years.

Therefore, the LCOS for this battery is $0.103/kWh. In the United States, retail electricity prices average $0.112/kWh.

The average cost of electricity in Southern California is $0.25/kWh, but can reach $0.66/kWh during peak summer (4pm-9pm). In addition, electricity bills are rising steadily (an average of 1.7% per year over the past decade).

Can I save money and make money with LiFePo4 batteries?

With an energy storage system, you can actually make money (ESS). The ESS is a plug-and-play device that combines a solar charger, inverter and battery storage. It can be connected to the solar panel battery bank indoor as well as the electric grid.

Without solar panels, you can charge your ESS for $0.25/kWh during off-peak hours and sell it back to the grid during peak hours for a higher price.

Let’s run the numbers:

If you sell it for $0.66/kWh and make a profit of $0.25/kWh, then your profit is $0.25/kWh.

Solar power is the cheapest source of electricity, so if you get your power from solar panels, you may make more money.

Pls remember that this is only a preliminary estimate and more precise calculations should be made, but this is how cheap LiFePO4 batteries are in practice.

What can we use for lithium iron phosphate battery

LiFePo4 batteries have a wide range of applications due to their high power density (Wh/kg), high energy density (Wh/kg), and long life (up to 10 years).

I’ve listed some of the many uses for LiFePo4 batteries below:

l Energy Storage System (ESS), such as Fortress Power Evault.

l Solar batteries with solar panels to replace lead-acid type batteries.

l Provide portable solar generators and DIY solar power systems for camping.

l Electric vehicle batteries are an application that requires large amounts of power, storage, and durability. During car acceleration, lithium iron phosphate batteries can provide high current pulses.

l Solar water pumps system.

l Provide electric bicycles and scooters.

Is it safe enough to use lithium iron phosphate batteries in room

LiFePo4 battery is the safest lithium battery at present.

They are protected by a hermetically sealed aluminum housing that can withstand extreme temperatures, pressures, punctures and bumps.

So they are totally no need to maintenance including a BMS, what we call battery management system.

They include safety equipment that monitors and manages each battery cell individually. By disconnecting problematic battery cells, it protects them from overcharge/discharge, short circuits, and abnormal temperature changes. It also ensures cell voltage balance for consistent charging and discharging.

Will my LiFePO4 battery explode

As mentioned earlier, LiFePo4 batteries are very safe due to the safety device. There is no danger of explosion and fire during the usual operation, also no leakage will happen.

However, lithium iron phosphate can detonate in one of two situations:

1. LiFePo4 factory default value:

The mass production of lithium iron phosphate batteries is in the hundreds of millions, and the possibility of battery failure is very small. Estimated at 1 in 10,000,000, this is quite low compared to the risk of being struck by lightning (1 in 13,000).

2. LiFePo4 in the presence of external heat (over 200°C):

Several investigations were conducted to understand how different lithium batteries would react when overheated. LiFePo4 has been shown to be the safest of all lithium-ion batteries due to its low temperature rise. Also, due to the highest thermal runaway, they won’t spread the fire to other batteries.

LiFePo4 batteries require temperatures in excess of 270°C to burn.

Do lithium iron phosphate batteries need a specified charger

Charging LiFePO4 batteries requires a dedicated charger with a charging curve (voltage limit) suitable for Li-ion batteries.

However, since the voltage is limited within the allowable range of lithium batteries, you can also use lead acid battery chargers.

The charging curve of a LiFePO4 battery is divided into two steps:

l The first stage: constant current

l The second stage: constant pressure

The only difference between these two phases and the charging profiles of GEL and AGM batteries is the charging speed. Unlike lead-acid batteries that can only be charged at 0.1-0.3C (10-30% of their maximum current capacity), LiFePO4 batteries can be charged at 0.3C-1C.

Take a 12V–100AH lithium battery as an example, it can withstand up to 1000W of charging power while for AGM or GEL, it can only use 300W of charging power.

Let’s take a much closer look at the different stages of lithium battery charging.

Stage 1: constant current

The LiFePo4 battery will back to 90% of its capacity by only charging 1 to 2 hours at maximum charge current in the first stage.

Stage 2: constant voltage

The second phase will help restore the remaining 10% of capacity. Phase 2 may take up to 20 minutes to complete.

The lithium battery can be a full charged for only 2-3 hours if your battery charger offers enough current. You can see its charging time is much shorter than GEL or AGM batteries, while it takes 10 to 12 hours to the fully charge.

Fast chargers are not easy to buy in many countries. At present, the strongest chargers are in China, some of then even reach 400W.

Solar power is the most efficient way to quickly charge lithium batteries. Solar energy can pull up to 100 amps into a depleted battery.

How to store LiFePo4 batteries

LiFePO4 batteries should be put at 60-80% capacity in a dry, mild environment (about 77°F).

The self-discharge rate is about 2% to 3% per month.

Make sure the battery temperature does not drop below 32°F as this may cause irreversible damage to the lithium battery.

Are LiFePo4 solar batteries the best

I think LiFePO4 is currently the best solar bettery now. It is more compact than lead acid type battery, stores more energy, and lasts longer.

It is also ideal for solar power as it allows for fast charging and discharging.

The prime disadvantage of LiFePO4 technology is that it degrades at low temperatures (below 32°F), making it can’t suit for cold regions.

LTO (Lithium Titanate Oxide) is an improved lithium battery and probably the biggest replacement for LFP.

The LTO battery operates in a temperature range of -40°F to 140°F and has excellent charge and discharge speeds of up to 15C (15 times its rated current), allowing it to be fully charged in 15 minutes. Plus, they have over 15,000 cycles for a long service life.

Conclusion:

Lithium iron phosphate batteries are undoubtedly the largest batteries available.

Lithium iron phosphate battery technology can be regarded the most significant technological advance in the field of electricity storage.It paves the way for a clean energy storage revolution.

But there is still some progress space for LiFePO4 batteries, such as its durability, energy density, and charging speed.