Lithium ion Solar Charge Controller Guide

Why Lithium ion solar charge controller?

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. A 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 case of the lithium-ion battery makes energy storage more efficient.

What is Lithium-ion solar charge controller?

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

Lithium-ion battery[1]: One-third of the global battery market is captured by lithium-ion technology because of their high density and lightweight. These have high cell voltage, fast charging, and low self-discharge and 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 to catch fire or explode. These batteries should not be exposed to water as they are highly reactive to it. 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 of 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:

Li-ion battery charging graph1
Li-ion battery charging graph1

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 battery to the load connected. Solar charge controllers are mainly of two types:

PWM (Pulse width modulation): This is less efficient but fairly cheap.

MPPT (Maximum power point tracker): 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 charging of Li-ion battery.

How and when to use Lithium ion solar charge controller?

A PWM or MPPT solar charge controller is used to regulate 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. Charge controller specially designed for Li-ion battery should be used as Li-ion battery has a specific algorithm to charge. In a solar photovoltaic system generating electricity with certain voltage and current from panel or array of panels is first transmitted to the charge controller. Depending on the type of charge controller (PWM or MPPPT), 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 case of Li-ion battery, the charge controller is set to charge Li-ion battery in phases. Efficiently charging and discharging of the battery, in this case, is important and marks as 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 charge controller depending on the capacity and battery type is essential for the system’s performance. Like the model HP2460 from can be used for Li-ion battery of around 40-50A.

From ZHCSolar: HP2460 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 a 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?

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, water pumps, hybrid vehicles or any off-grid facility where Li-ion 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. Controller can be kept near the battery to manage it with the same as required.


It is imperative to use a charge controller for charging a 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 offer a number of options in solar charge controller to be used in regulating the flow of charge to Li-ion batteries or Li-ion power bank.


Check out this Product list of Solar Charge Controller for Lithium ion Battery


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