Lithium ion Solar Charge Controller Guide

Lithium ion Solar Charge Controller Guide

Why Lithium ion solar charge controller?

the lithium ion solar charge controller is a kind of charge controller specialized charging lithium ion batteries as the lithium battery are gaining popularity in recent off grid applications.

A stand-alone photovoltaic solar energy system connected to batteries requires a charge controller. The charge controller is used to regulate the charging of a battery or battery bank. Without a charge controller, a battery will not charge efficiently and may get ruined due to overcharging or discharging.

the solar systems need batteries to store the power generated by the solar power, and the role of charge controller is regulation the process and protect the battery bank.

A proper lithium solar charge controller can efficiently increase the charging ability by adjust the current output and extend the battery life.

both the MPPT function and PWM function inbuilt can make the charge controller play the role. but an MPPT charger can do the job in higher level and give the max power out.

A lithium ion solar charge controller is required similarly for LifePO4 Battery and lithium-ion batteries. There are various types of batteries available in the market with the technological advancement for high efficiency and options available in chemistry to do so.

The lithium-ion battery is no exception in this race of batteries and is highly efficient as compared to other battery technologies. A charge controller makes the working of the battery to the highest possible level and using it in the case of the lithium-ion battery makes energy storage more efficient.

Useful Topic: Best 10 Lithium Solar Charge Controller Comparison & Ratings of 2022-2023

What is Lithium-ion solar charge controller?

A charge controller which regulates the charging of a lithium-ion battery is a lithium battery solar charge controller.

Lithium-ion battery[1]: One-third of the global battery market is captured by lithium-ion technology because of its high density and lightweight. These have high cell voltage, fast charging, and low self-discharge, and a good lifetime when deep cycled. High cost and safety are two limiting factors of lithium ion batteries. Per watt, lithium ion batteries are costlier than lead-acid batteries. To protect the battery from thermal runaway, lithium ion battery needs circuitry built-in the battery pack, otherwise, it may catch fire or explode. These batteries should not be exposed to water as they are highly reactive to them.

Lithium ion Charge Graph
Lithium ion Charge Graph

Energy is stored in lithium ions which migrate from cathode to anode in rechargeable lithium ion battery. Electrons are freed from anode undergoing oxidation to conduct current during discharge, cathode gains electrons in the same process undergoing reduction. In these batteries, the cathode is made up of lithium metal oxide and the anode of porous carbon. The liquid electrolyte is present in most Li-ion batteries and some have polymer (gel) electrolyte to carry charge between anode and cathode. Li-ion battery charges in phases which can be seen in the graph below:

Solar charge controller: Electricity generated from solar panels is always at different voltage and current levels, depending on the weather conditions and time of the day. A charge controller regulates the flow of charge from the solar panel to the battery. Also, it regulates the flow of charge from the battery to the load connected. Solar charge controllers are mainly of two types:

PWM (Pulse width modulation) charge controller for lifepo4: This is less efficient but fairly cheap.

MPPT (Maximum Power Point Tracking) charge controller for lifepo4: This is highly efficient but costly.

It is on the choice of installer or buyer to go with PWM or MPPT as both technologies can be used to regulate the charging of Li-ion batteries.

How and when to use Lithium ion solar charge controller?

A PWM or MPPT solar charge controller is used to regulate the charging of the battery in a stand-alone solar photovoltaic system. A lithium-ion solar charge controller is used when a Li-ion battery is used as power storage in the system. A charge controller specially designed for Li-ion battery should be used as the Lifepo4 battery has a specific algorithm to charge. In a solar photovoltaic system generating electricity with a certain voltage and current from a panel or array of panels is first transmitted to the charge controller.

Depending on the type of lithium battery solar charge controller (PWM or MPPT), the regulation of charge takes place. It is very important to regulate the charge as it is connected to the battery to charge it. In the case of charging lithium batteries with solar, the charge controller is set to charge Li-ion batteries in phases. Efficiently charging and discharging the battery, in this case, is important and marks a successful installation if the efficiency of the system can be kept to its peak.

Many different types of solar charge controllers are supplied by with different amperage and capacities. Choosing the right capacity of the charge controller depending on the capacity and battery type is essential for the system’s performance. Like the model WP5048D from can be used for Li-ion batteries of around 40-50A.

From ZHCSolar: WP5048D 50 Amp 48V Solar Charge Controller

It is very important to have all the components of the solar system in an appropriate ratio, no less or more than required. Depending on the load demand or connected (expected) load to be supplied by solar photovoltaic generation the solar panels should be installed and relevant to the panels, charge controllers and batteries should be installed. Losses in the system should be considered to design and implement the whole system.

Li-ion batteries either the liquid electrolyte or gel electrolyte type is an efficient option to store energy in the most appropriate way. Being costly compared to other battery types, these batteries should be operated with the highest possible efficiency and performance to last them long. Specific solar charge controllers for these batteries can make this possible and should be kept as a priority in the system.

Where Lithium ion solar charge controller be used?

A stand-alone solar generation system with battery storage in the form of Li-ion battery requires this charge controller. This is a specific solar charge controller for Li-ion batteries and installed for the same. Any facility like RV, yachts, Boat, water pumps, hybrid vehicles, or any off-grid facility where Lifepo4 battery is used required this specific solar charge controller.

This should be installed in a manner that the transmission losses do not occur wherever installed. The transmission lines from panels to the controller and from the controller to the battery should be efficient with minimal losses. a Lithium battery solar Controller can be kept near the battery to manage it with the same as required.

MPPT charge controller vs pwm charge controller which is better for lithium-ion batteries?

mppt charge controller is more recommend if you have enough budgets, as nowadays Many mppt controllers have special features attached, such as Bluetooth remote control, lcd display can also showcase more functions, and the temperature sensor is more precise.

when the lithium battery systems is applied as the car battery, use a smartphone app to conduct the remote control is very convenient.

in most cases, solar power golf carts and ebikes are installed with lithium ion batteries, thus required the boost charge controller, boost mppt controller can increase the charge current with higher voltage when have limit space for the solar array installation.

Lead-acid Vs lithium-ion batteries: Which is best for Solar? 

In solar energy systems, lithium batteries are increasingly used and even have the tendency to completely replace lead-acid batteries.

Here are a few major differences:

  1.  Durability/Battery Life: lead-acid battery life is generally about 2 years, while lithium batteries are more durable, the life of more than 4-5 years. and lead-acid battery cycle fully charged and discharged generally within 300 times, while lithium batteries are fully charged and discharged cycle times more than 500 times.
  2. Efficiency: Lithium batteries are more efficient at charging and discharging. This means that you can store and use more solar energy under the same conditions.As an example, lead-acid batteries are typically only 80-85% efficient. This means that if you have 1000 watts of solar energy going into the battery, after the charging and discharging process, only 800-850 watts will be available.Lithium batteries are over 95% efficient. Under the same conditions, you would have more than 950 watts available.Higher efficiency means that your battery charges faster. Depending on your system configuration, it may also mean you can save more money.
  3. Weight: The energy density of the lithium-ion solar battery is generally 200~260wh/g, and lithium battery is 3~5 times of lead-acid, which means that with the same capacity, the weight of a lead-acid battery is 3~5 times of a lithium battery, so in the lightweight energy storage device, lithium battery occupies the absolute advantage.Lead-acid batteries are generally in the range of 50~70wh/g, with low energy density and too bulky.
  4. Maintenance: Lithium batteries do not require special maintenance and can provide stable power for a long time, while lead-acid batteries require different maintenance depending on the types.
  5. Safety: Lithium batteries due to the stability of the cathode material and reliable safety design, lithium iron phosphate batteries have been rigorously tested for safety, even in violent collisions will not produce an explosion, lithium iron phosphate high thermal stability, electrolyte oxidation capacity is low, and therefore high safety.    Lead-acid batteries in the charge and discharge or use will discharge gas, if the vent is blocked, it will lead to gas discharge where an explosion occurs, the electrolyte (dilute sulfuric acid) spewed out is a corrosive liquid, will be corrosive to many objects, and the gas generated in the charging process is explosive.
  6. Battery Management System: Nowadays, lithium batteries have become more and more intelligent and functional. The lithium battery can now be adjusted according to the user’s needs, length of use, etc. Many lithium batteries can be installed with a BMS management system, which can check the status of the battery in real-time on the cell phone. The BMS is also able to detect the current and voltage of the battery, and if there is an abnormality, the BMS system can automatically adjust it.

In today’s global trend of new energy development, compared with lead-acid batteries, lithium solar batteries are relatively green in both production and recycling.

Types of solar charging lithium batteries

The most popular is lithium iron phosphate batteries, the battery is not like lead-acid batteries have a memory effect, after more than 1600 charges, the battery’s storage capacity can still reach 85%, compared with lead-acid batteries, lithium batteries have the advantages of a lightweight, high capacity, long service life.

most lifepo4 battery charger are able to charge agm gel and lead acid batteries meanwhile by adjust the parameters whiles setting the solar controller.

Advantages of lithium battery for solar

Green and environmental friendly

The lithium battery can be installed directly under the solar panel, small size and lightweight to reduce construction costs

Long service life,lifepo4 battery is 3-5 times longer than traditional lead-acid batteries;

High and low-temperature resistance, can be used in -4°F -140°F environment, special lithium battery can be used in -49°F environment;

Maintenance-free, good performance

USB output DC for mobile devices.

lithium batteries work better with inverter in off-grid system.

in solar power systems,lithium battery is getting popular then before.

lithium battery supports wide range applications.


It is imperative to use a charge controller for charging a 18650 battery and its efficient use. In the case of LiFePo4 battery, it becomes even more important to use a charge controller. Li-ion battery is costlier than the other options available and is more efficient in comparison. Being costly it becomes necessary to use a specific charge controller as mentioned above to make the life of Li-ion battery longer and safe. Companies like zhcsolar offer a number of options in the solar charge controller to be used in regulating the flow of charge to Li-ion batteries or Li-ion power banks.

Editor’s Product Review: Best 10 Lithium Solar Charge Controller Comparison & Ratings of 2020-2021

How to Choose the Best MPPT Solar Charge Controller for Lithium Battery:

ZHCSolar Offers the Best MPPT Solar Charge Controller in the Market, Get Free Shipping, and Buy Now.

For More information, Please refer to MPPT Charge Controller Ultimate Guide (2021)

Size Calculator for choosing the right ampere controller is ready to use.


Check out this Best Choice List of Solar Charge Controller for Lithium ion Battery and lithium ion battery for rv solar



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