2022 Lead Acid Batteries Vs Lithium Ion Batteries Guide

In recent years, many people have turned to lithium-ion batteries as the first choice for home solar storage systems. Because people prefer lithium-ion batteries to lead-acid batteries. But that doesn’t mean that a lead-acid battery loses its function. Lead-acid battery technology continues to evolve in the right direction, such as Sonnenschein and BAE introducing high-performance sealed tubular gel batteries, and YHIPower, GS, and Nada launching advanced lead-carbon batteries.

Today, we will talk in detail about the advantages and disadvantages of the two more popular lithium-ion batteries and advanced deep-cycle lead carbon and lead-acid batteries for comparison, you can go to better understand a little. Because each cell type depends on its own discharge rate, depth, and cycle life, direct comparison is not easy. A little more specific criteria and parameters can be more fully answered inside the solar parameter table.

Readers should note that this article does not include lead-acid batteries soaked in water or not sealed, as their maintenance requires high attention, especially in ventilated areas, and any cost savings can be offset by regular maintenance efforts required throughout the battery life.


Best batteries for solar storage

Lithium-ion batteries are by far the best choice as storage batteries because of their high density energy and efficiency. However, more than one type of lithium-ion battery is being used. Most homes usually use lithium storage batteries as lithium iron phosphate (LiFePO4 or LFP) because of their lower cost and longer cycle life. However, some famous manufacturers such as LG chem and Tesla use lithium NMC batteries, and you can read more about lithium-ion batteries here. For this article, we focus on describing the popular manufacturer Pylontech in China and the leading US manufacturer Simpliph.


Battery Efficiency

Charge and discharge efficiency or loss during the use process this process is called round-trip efficiency and also called battery efficiency. Because of the laws of physics, the transfer of energy from one form to another results in energy loss. In this case, the battery is transferred from chemical energy to electricity during discharge, and from electric energy to chemical energy during charging. Generally speaking, the energy lost during transmission will be a bit more for lead-acid batteries, about 15-20%, and a bit less for lithium-ion batteries, about 2-8%.

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Another problem with lead-carbon or lead-acid battery systems is that they charge longer during charging as compared to lithium-ion batteries. The depth of discharge varies between batteries, and a typical lead-acid battery has a recharge cycle of two to four hours. This means that when lithium-ion batteries are charged in bad weather, the charging efficiency can be very low, leaving the battery unable to be fully charged and then having a bad impact on battery life. In contrast, lithium-ion batteries can be charged quickly in bad weather, in 1 to 2 hours, and can absorb energy faster and efficiently. Compared with lead-ion batteries, lithium-ion batteries are that they can tolerate partial charging (POS) for a long time without sulfation issues or degradation. Lead-acid batteries must be adequately charged during the winter, otherwise, it will be very easy to greatly reduce the life of most lead-acid (AGM or gel) batteries.


Battery Capacity – Depth Of Discharge

As a general guide, conventional lead-acid (gel and AGM) batteries typically discharge no more than 30-40% a day, while lithium (LFP) batteries are designed to discharge up to 90% (10%SOC).


Usable battery capacity comparison

** Always refer to manufacturers’ specifications. The warranty may not work if the depth emissions are below the range specified in the manufacturer’s warranty conditions.


Lead-acid battery capacity

Traditional gel and AGM cells are durable without advanced tubular gel and lead carbon cells, and advanced tubular gels and lead carbon cells can maintain greater discharge depth, up to 70% available (in backup situations). However, if advanced tubular gels and lead-carbon batteries discharge very deep every day, the battery cycle life will also be severely reduced.

48v 50ah lithium battery

We recommend setting the maximum discharge depth for lead acid and lead carbon cells to less than or equal to 40% and less than or equal to 70% in standby cases. Lithium-ion batteries also have a situation where they can be discharged from 70-90% on a daily basis, and from 95 to 100% if they are already in a backup situation.

* Always refer to the battery manufacturer’s specifications.


Advantages Of Lead-Acid Batteries

Lead-acid battery technology is very reliable, as it has been around for more than 100 years. Also, it is very safe and reliable if sized and installed correctly. For off-grid systems, the most trusted batteries are still lead-acid batteries… A properly designed system can usually last longer than ten years. One good thing about lead-acid battery pack is that it has no cut-off point for the depth of discharge, so if there is an emergency, the lead-acid battery pack can continue to release power until the voltage reaches the cut-off point of the inverter, the bad thing about this is that it may reduce the life of the lead-acid battery. This is also what distinguishes lead-acid batteries from lithium-ion batteries. Deep-cycle lead-acid batteries have been around for decades, but recent advanced, sealed, gel-deep-cycle batteries give service-free sealed lead-acid batteries a service life of up to 15 years.

48v 50ah lithium battery-1

There are many mature companies around the world that produce high-quality sealed tubular gel lead-based acid (technically known as OPzV).


Leading lead-acid battery manufacturers:

Narada (Lead-carbon)

YHI Power (Lead-carbon)

Trojan Battery

GS Yuasa





We chose BAE solar PVV Gel lead-acid cells and the NaradaREXC to represent lead carbon for the following comparison.


Advantages Of Lithium Batteries

On one side, because of its extremely high energy density, the most obvious advantages of lithium-ion batteries are their compact size and weight. Because of the higher discharge depth in lithium batteries, it is agreed that the size and weight of lithium LFP batteries are about 30% of the equivalent lead-acid batteries. On the other hand, because lithium-ion battery systems are generally composed of smaller, tractable modules ranging from 2 to 4 kWh, people can provide more flexibility when sizing the system.

24v 100ah Lifepo4 battery1

Lithium-ion batteries have a much lower resistance when compared to lead-acid batteries. The biggest advantage of lithium with low resistance is its low loss during the charge and discharge process, so the round-trip efficiency is very high. Therefore, at a high load (* 48V), the voltage of lithium usually does not fluctuate more than 1-2V. This will be explained in more detail at the end of this article.


Detailed Battery Breakdown

Simpliphi PHI

Since 2002, the leading developer of lithium-ion batteries is based in the United States and has the advantage of having extremely high cycle life, safety, and stability. One of the only fully modular battery systems in the home battery market is the PHI series of lithium iron phosphate batteries (also known as lithium iron phosphate or LFP).

The PHI range is fully scalable, with most residential lithium battery systems that are fixed capacity or limited to 2-4 modules in parallel, only truly subject to the inverter and solar array capacity available. This PHI battery does not require thermal conditioning, cooling, or ventilation.

48v 200Ah Lifepo4 battery-1

Given that the lithium LFP is the most stable lithium chemical and has a proven record, the PHI series now seems to be one of the only “declining” lead-acid battery alternatives and one of the most powerful battery systems on the market.

SimpliPhi has the advantage that its batteries have a 10,000 cycles/10 years warranty (80% DoD) and a 3500 cycles/10 years warranty, 100% D, which indirectly shows that the warranty is the best. Of course, the best warranty also has some conditions, the battery operating temperature needs to be 0-43℃ and the charge/discharge rate cannot be greater than 1.6KW, so as to comply with the warranty.



One of the first available lithium-ion batteries, the tower technology lithium iron phosphate (LFP) batteries, was encapsulated with the lithium battery and battery management system in a simple rack mounting unit. The invention of the U.S. 2000B, which can replace the Extra2000 to some extent, has many improvements in his overall, as well as a more robust connection cable… Because the US2000B is a 2.4 kWh module of the same size (previously with a touch screen interface), it allows people to easily set up and monitor and connect to multiple units in parallel. In general, PylonTech also offers higher voltage modules for its own distributors, which are often rebranded and used by many distributors and traders.24v 100ah Lifepo4 battery1

The most stable of all lithium battery chemicals inside is lithium iron phosphate (LFP), especially around Australia, where it is often required to operate at temperatures higher than 40 degrees Celsius, which is the cut-off temperature for lithium-ion batteries of 50 degrees Celsius. The cycle life of the LFP claimed to have 6000 cycles is also quite high at an 80% discharge depth, although we are not clear what is the end of life (EOL) retention capacity after this cycle?LFP warranty is for 5 years if specified for 60%EOL capacity, LFP for 10 year warranty. The updated US 2000B batteries retail for the same as the previous additional 2000. The battery module operates at a nominal voltage of 48V and now has a higher peak power output of 5kW (previous model 2.2kW).


Narada Lead-Carbon

ZHEJIANG Narada Power Source Co is a Chinese company focusing on power systems and energy storage solutions.REX series lead-carbon battery technology has high capacitance and high conductivity nanocarbon materials on negative electrodes. The company announced that the series can be charged more quickly because of the advantages of combining supercapacitors and lead-acid batteries. Compared to conventional lead-acid batteries, lead-carbon battery technology not only provides high power, long cycle life, and fast charge and discharge but also provides higher energy density.

48v 100ah lifepo4 battery-1

However, these batteries require multiple strings of batteries at an available capacity of more than 6 kilowatt-hours, because the lead-carbon battery technology currently only supports the large 6V and 12V modules. This situation is not conducive to broadening the market for large systems, but it is suitable for most domestic hybrid settings. Furthermore, this is not optimal for mixing where full discharge is more likely to exceed 12 hours or less, as the rated capacity is available only available at a very slow discharge rate (C100). Because the researchers claim 3,000 cycles at 40℃, they could theoretically last longer at lower temperatures.


BAE Gel Lead-Acid

The BAE Gel Secura battery is a high-quality German-made lead-acid battery, designed specifically for off-grid and hybrid devices.BAE produces cells of different voltage configurations and sizes, and in the description below, we will focus on the gel SecuraPVV solar (tubular gel) series.BAE has been producing lead-acid batteries for over 100 years now, and they have the latest Gel Secura PVV battery design with both advanced tubular plate electrodes, corrosion-resistant lead-calcium alloy, and a rugged polyester woven glove mesh. The fully sealed maintenance-free battery can be performed under harsh conditions and high temperatures due to the use of VRLA technology.


Space And Weight

For many fixtures, weight is often seen as a minor problem. But if the space is limited, then the lead-acid battery pack will be very heavy, which requires special shelf systems in small areas.

Lead-acid batteries can be prone to problems due to space issues because they take up quite a bit of space and require frequent ventilation and airflow so as to allow any trace gases to shoot out while charging and to keep the battery cool at higher temperatures… Another advantage is that the lithium battery module does not require the same amount of ventilation because it does not emit any volatile gas during charging. This means that they can usually be stored in most uninhabitable rooms or garages without creating danger.

48v 100ah lifepo4 battery-1

In addition, many lithium-ion batteries have a BMS (internal battery monitoring system,) his role is to monitor the overall battery voltage and battery temperature, if the temperature exceeds 45 degrees Celsius, it will directly shut down the lithium-ion battery. BMS protection is a good safety feature, but it should be reminded that lithium batteries cannot be mounted outside in hot, unventilated places or confined spaces.


Batteries For Off-Grid Systems

Recently, lithium battery systems have been very popular in off-grid installations because of their scalability and high efficiency (95-98%).In contrast, lead acid batteries cannot add additional capacity after installation because the capacity or size of the lead acid battery pack is fixed.

48v 50ah lithium battery

If space is a problem, lead acid also has a much lower energy density than lithium batteries and is heavier and less compact. A common problem with lead-acid batteries is sulfur acidification. The biggest advantage of lithium, by contrast, may be its ability to maintain a low charge state (partial charge state) for a long time, without any negative effects.

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