Understanding UPS Battery Types: Lead-Acid vs. LiFePO4 Skip to content
Understanding UPS Battery Types: Lead-Acid vs. LiFePO4

Understanding UPS Battery Types: Lead-Acid vs. LiFePO4

Unexpectedly, your UPS battery can die, interrupting the UPS's functionality. That usually intrigues the beginning of an impulsive hunt for a new, fully charged battery. It's time to decide on the most suitable battery type for your UPS system.

Lithium Iron Phosphate batteries (LiFePO4) and lead acid batteries are the most popular UPS battery types. As much as LiFePO4 is more potent than the lead acid battery type, it’s easy to be overwhelmed when choosing one over the other. 

This article clarifies them simply and concisely to your level of understanding. Know the differences and eventually choose wisely.

Knowing Lead Acid Batteries

Lead-acid batteries are the oldest rechargeable batteries currently in use. They were the first invention of a rechargeable battery, launched in the mid-1800s. Surprisingly, they remained top of the game even after newer inventions of modern rechargeable batteries.  

However, over time, there have been technological improvements in the product. So you find that lead acid batteries further divide into different types, the latest and most advanced being the AGM (Absorbed Glass Mat) type. Also, lead itself has been modified with the innovation of lead alloys to improve the efficiency of this battery. 

Understanding UPS Battery Types: Lead-Acid vs. LiFePO4

The Structure of the Battery Block

This answers your curiosity about what a lead-acid battery looks like. Its structure contains multiple parts that work symbiotically to dispense electrical charge to a connected system. 

Typically, a sealed battery comprises electrodes and an electrolyte (an anodic solution, mostly acidic). In this case, a lead-acid battery uses lead dioxide and spongy/porous lead as the electrodes and concentrated sulfuric acid as the electrolyte to produce electricity. 

These are the primary components of a lead acid battery:

  • Cathode (the positive plate): the lead dioxide (PbO2)
  • Anode (the negative plate): the sponge lead (Pb)
  • Electrolyte: concentrated sulphuric acid (mixed with water)
  • Porous separators positioned between the alternating cathode and anode plates

All these primary elements are encased within a plastic casing, which keeps them intact. The electrolyte fills the space left by the other elements within the compartment or battery casing. Therefore the plates and the separator immerse fully in the sulphuric acid solution for an electrochemical process. 

How the Lead Acid Battery Works

For laypeople, electrical power is generated through chemical reactions between the reactive components of the battery. A lead-acid battery can power your UPS courtesy of electron flow between the electrodes and electrolyte. 

Simply put in more detail, it’s more of an electrochemical circuit in which electrons flow from the negative plate, through the device powering it, and back to the positive plate. 

At the anode, the sponge lead reacts with the aqueous sulphuric acid, releasing electrons. Concurrently, another reaction takes place at the cathode, creating a need to take up the electrons accumulating at the anode. It’s pure chemistry happening in the battery casing, and just learning about it makes the entire learning journey beautiful.

Pros and Cons of Lead Acid Batteries

Here’s what to expect in a lead-acid battery. After determining the advantages, you'll evaluate the limitations of this UPS battery type to determine whether a lead-acid battery is your choice. 

Advantages (Pros)

  • Wide availability: As said earlier, lead-acid batteries have existed for many decades due to their widespread use. They are very popular and are widely sold in retail stores, hardware shops, and even online stores worldwide.
  • Cost-effectiveness: This battery is one of the most affordable on the market. Choosing a lead acid battery makes it easy to meet your low budget.
  • Durability and resilience: Lead-acid batteries are robust in structure and easily provide power even in harsh environments, such as extremely high temperatures. They function effectively in both cold and hot conditions without malfunctioning. 
  • Eco-friendliness:  This is a sustainable battery type as it’s recyclable. It reduces the need to source new materials for its manufacture, saving on global resources and reducing environmental deterioration. The lead components in an old lead-acid battery are easily re-used in the creation of new lead-acid batteries.
Limitations (Cons)
  • Heavy and bulky battery: The high lead content makes lead-acid batteries heavy and difficult to move around. Therefore, they are most suitable in applications where portability isn’t necessary. 
  • Limited cycle life: Lead-acid batteries have shorter charge-discharge cycles compared to emerging modern batteries, hence a shorter lifespan. The cycle life ranges between 500 and 1000 cycles, varying with the type of lead-acid battery. 
  • Maintenance requirements:  The flooded lead acid battery type, in particular,  demands periodic maintenance. You’ll keep checking the electrolyte levels and refilling the electrolyte in the battery using distilled or de-ionized water. And you have to be keen not to overwater or underwater the battery. 
Understanding UPS Battery Types: Lead-Acid vs. LiFePO4

LiFePO4 Batteries

When it comes to LiFePO4 technology, you’re dealing with a lightweight battery that requires zero maintenance, offers greater performance and efficiency, and is quite expensive. Sometimes referred to as LFP batteries, LIFePO4 (Lithium Iron Phosphate) batteries are a type of lithium-ion battery applicable to power backup systems like the UPS.

Like lead-acid batteries, lithium-ion batteries belong to the rechargeable battery family. The first ever lithium-ion battery came about in the 1990s. It has developed over the years through improvements in performance and reliability and is booming in the current technology-driven battery market.

Initially, this battery type was associated with laptops, mobile phones, cameras, and most small portable electronic devices. Later, it advanced, and its use spread to power backup supplies, electric vehicles, and other large systems that demand high power.

Composition of the LiFePO4 Batteries

Starting with the basics, LiFePO4 batteries are composed of lithium, iron, and phosphate, which is the material forming the cathode. Because lithium is the key element,  they are considered a type of lithium-ion battery. 

The anode section is made of graphite and carbon materials, while the electrolyte is basically a lithium salt dissolved in an organic solvent. Mostly, it’s a mixture of lithium hexafluorophosphate and ethylene carbonate or dimethyl carbonate, making up the electrolyte of a LiFePO4 battery.  

Similarly, the electrode plates are kept apart using a porous polymeric separator. All these components are sealed in an airtight enclosure in the form of a battery case, just like in lead-acid batteries. 

How LiFePO4 Battery Functions

While discharging, chemical energy is converted to electrical energy through electrochemical reactions within the LiFePO4 system. The vice versa happens when the battery is charged to store more power. This battery operates through alternating charging and discharging cycles. 

In times of providing electrical power, the lithium ions disassociate from the cathode and are attracted by the graphite anode. This flow of ions, specifically electrons, triggers an electric current that powers the connected UPS. Generally, batteries function under the same principle of electrolysis.

Understanding UPS Battery Types: Lead-Acid vs. LiFePO4

Pros and Cons of LiFePO4 Batteries

LiFePO4 batteries have become very popular recently for the following reasons. However, the downsides compared with other types of batteries will leave you with a stream of thoughts. We recommend selecting according to your pre-determined needs. 

Advantages (Pros)

  • High energy density: LiFePO4 batteries have high energy density in the sense that they store plenty of energy in a small battery piece. 
  • Lightweight and compact: Most LiFePO4 batteries are small and light because the materials used to make them are light and have a large energy capacity per unit weight. 
  • Long battery life: These batteries accommodate 2000 charging cycles, which could go up to 10,000 cycles in a commercial setting. As such, they last long, spanning 5-10 years under good maintenance. 
  • Environmental-friendly: They are not composed of toxic metals like lead, cobalt, and cadmium, so they are completely environmentally safe.

Limitations (Cons)

  • Higher Initial Cost: The LiFePO4 battery will cost a lot of money to purchase. However, its long-term benefits and lifespan make it a valuable investment for your UPS
  • Complex management requirements: The LiFePO4 battery utilizes a complex Battery Management System (BMS), which requires regular updates to maintain the battery’s  efficient operations
  • Vulnerability to harsh conditions: Exposure to extremely high or low temperatures catalyzes poor performance and damages the LiFePO4 battery, reducing its lifespan. You’ll notice the battery charges slower, especially when it’s too cold. 
Understanding UPS Battery Types: Lead-Acid vs. LiFePO4

Comparing Lead Acid Batteries with LiFePO4 Batteries

Now, we analyze the differences between lead acid batteries and LiFePO4 batteries through comparisons in various aspects. 


Lead acid batteries are cheaper than LiFePO4 batteries when you look at the upfront purchase prices. If you’re working with a limited budget, lead-acid batteries outdo LifePO4 batteries. However, LifePO4 batteries are more worthwhile in the long run when you consider their extended durability and greater functionality. 

Performance Metrics Comparison

  • Energy Efficiency: Compared to lead-acid batteries, LiFePO4 batteries are more energy efficient. They have a higher energy density, which means they have greater storage capacity for energy in a smaller space. 
  • Life Cycles and Durability: LiFePO4 batteries have 4-10 times the charging and discharging cycles of lead-acid batteries. The more life cycles, the more robust and durable they are.
  • Environmental Impact: LiFePO4 batteries are completely safe for the environment as they contain no toxic metals or elements. On the other hand, lead-acid batteries are environmentally friendly, considering lead is recyclable. Still, they are likely to cause environmental degradation because lead is a highly toxic metal, and sulfuric acid is highly corrosive.
Understanding UPS Battery Types: Lead-Acid vs. LiFePO4

Application Suitability

LiFePO4 batteries are mostly suitable for large UPSs where long-lasting power is needed to run systems. These are often large-scale commercial places and office settings with the prevalent use of computers and telecommunication equipment. Space consumption, the battery’s reliability, long-term use, and cost savings are often the most prioritized concerns.

If your UPS is small or medium-sized, choose to work with lead-acid batteries. They’re most recommended for power back-ups in homes and commercial centers where the initial cost is considered over the long-term value, and space is barely a consideration. 

Understanding UPS Battery Types: Lead-Acid vs. LiFePO4

The Bottomline

Whether you’re going for LiFePO4 or lead-acid batteries, outline your budget and space availability and assess the various features and maintenance requirements before buying. None outsmarts the other completely, as your UPS battery choice will depend on the energy needs to be met.

Otherwise, get yourself a high-quality LiFePO4 battery or UPS system from GoldenMate Energy. We always have your power storage interests at heart. Remember also to check out our comprehensive guide, which will help you in your next purchase.

Cart 0

Your cart is currently empty.

Start Shopping