LiFePO4 vs. Lead Acid: Which One Is Right for You?

lifepo4 vs lead acid

Batteries are widely used in our lives as energy storage devices. The market’s most popular batteries can be divided into Lead-acid and lithium-iron phosphate(LiFePO4 or LFP) batteries.

As LFP batteries are used more and more widely, traditional lead-acid batteries have been gradually replaced by new-performance LiFePO4 batteries.

LiFePo4 vs. lead-acid batteries, So what are the advantages and disadvantages? Let’s take a quick look at the table below.

FeatureLiFePO4Lead Acid
Usable Capacity80+%30-35%
Life Cycles2000-5000200-300
ChargingFast Slow
Voltage SagNoYes
Energy Density120-170WH/KG40WH/KG
LiFePO4 vs. Lead Acid comparative sheet

What Is Lead Acid Battery?

A Lead-acid battery is a battery with electrodes mainly composed of lead and its oxides, and the electrolyte is a sulfuric acid solution. When a lead-acid battery is in a discharged state, the main component of the positive electrode is lead dioxide, and the main component of the negative electrode is lead; in the charged state, the main component of the positive and negative electrodes is lead sulfate.

The nominal voltage of a single lead-acid cell is 2.0V, which can be discharged to 1.5V and charged to 2.4V. In the application, six lead-acid cells are usually connected in series to form a nominal 12V lead-acid battery.

What Is LiFePO4 Battery?

LiFePO4 batteries use lithium iron phosphate as the positive electrode material, graphite as the negative electrode material, and the electrolyte is usually an organic solvent containing lithium salt.

The nominal voltage of the LiFePO4 cell is 3.2V, the end charge voltage is 3.65V, and the end discharge voltage is 2.0V. The working voltage range is between 3.0V-3.35v. 4 cells are connected in series to form a 12.8v LFP battery pack, also known as 4S.

Cycle Life

The cycle life of the lead-acid battery is about 200 times, and the maximum is 300 times, while the LiFePo4 battery can cycle up to 2000 times to 100% DOD (depth of discharge), which is 10 times that of lead-acid.

Usable Capacity Range

When an LFP battery is cycled to 20% DOD, 80% of its capacity is fully available. Due to limited charging, lead-acid batteries typically have only 30-35% usable capacity (50% SOC to 80-85% SOC). The usable capacity of a 300Ah LFP battery is equal to approximately 700Ah lead-acid batteries. 80% of the 300Ah LFP battery pack is 240ah and 35% of the 700Ah is 245Ah usable capacity.

Charging Speed

LFP battery has lower internal resistance and can tolerate higher charging current to realize fast charging, and the battery can be charged to 80% SOC in 40 minutes. A lead acid battery usually takes about 10 hours to fully charge due to the limitation of charging current and to prevent sulfation. Maintaining a “float” charge of 100% SOC is necessary.

What Is Sulfation?

The inevitable product of the redox reaction of lead-acid batteries is Pb2SO4, which will form irreversible lead sulfate crystals, which have poor electrical properties and large volume and will block the micropores on the plate, resulting in reduced capacity and eventually failure and scrapping.

Charging Efficiency

If the lead-acid battery is due to incomplete discharge in use, the capacity will quickly drop below the rated capacity value. This phenomenon is called the memory effect. LiFePo4 battery has no memory effect, and its electrolyte is more active. No matter what state the battery is in, it can be charged and used at any time, and there is no need to discharge it first and then charge it.


The volume of the LFP battery with the same specification and capacity is 2/3 of the volume of the lead-acid battery, and the weight is 1/3 of the lead-acid battery. The 12v400ah lead-acid battery bank weighs about 130 kg, and the 12v400ah LFP battery bank is only 50 kg. LFPs are lighter than lead-acid batteries and occupy less space.

Energy Density

The energy density of the lead acid battery is about 40WH/KG, and the LFP is about 120WH-170wh/KG.


Lead-acid batteries contain lead, which has a relatively large impact on the environment; LFP does not contain any heavy metals and rare metals, non-toxic, non-polluting, and is a green battery.


Lead acid batteries are less expensive to manufacture in terms of cost of materials and ease of production. However, depending on the cycle life, a cheaper battery won’t always translate to a substantially lower price tag.

Taking Amazon as an example, the LiFePO4 battery price is about 1.5 times that of the deep cycle AGM battery.

AGM-100Ah Bank=$200.00-50 USABLE Ah @50%DoD 200 cycles=$4/Ah/$1 per cycle
LFP-100Ah Bank=$300.00-100 USABLE Ah @100%DOD 2000 cycles=$3/Ah/$0.15 per cycle
LFP-100Ah Bank=$300.00-80 USABLE Ah @80%DOD 5000 cycles=$3.75/Ah/$0.06 per cycle

Frequently Asked Questions

Which is better, LiFePO4 or lead-acid battery?

LFP has the advantages of high energy density, high operating voltage, long cycle life, short charging time, and wide operating temperature, and is widely used in new energy vehicles, 3C products, and energy storage power supplies. Its performance far exceeds that of lead-acid batteries.

Can LiFePO4 replace lead-acid batteries?

The performance indicators of LiFePO4 batteries are all ahead of lead-acid batteries. The cycle life of LFP batteries can reach more than 2,000 times, while the cycle life of lead-acid batteries is only about 200 times. Regarding energy density, LFP batteries are significantly ahead, superimposed working voltage, working temperature, etc., and the replacement of lead-acid batteries is the development of the industry’s inevitable result.


Safety, cycle life, and price are the priority issues that everyone will consider before buying a battery. In addition, they will choose according to the actual situation of the application. If you want to invest in a battery bank that you can use off-grid regularly, LiFePO4 is the right choice.

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