LiFePO4 battery charging is an important thing for everyone who is using LiFePO4 batteries. A suitable charger can determine the life of the battery to a certain extent, and it has been proved that many people’s LiFePO4 batteries fail prematurely or have problems. The root cause is the lack of understanding of the charging process and the wrong choice of the charger. And some classic questions have been brought up all the time.
What is the principle of LiFePO4 Battery Charging?
There is no doubt that the principle of LiFePO4 battery charging is the same as that of other lithium batteries, which is the process of lithium ions passing through the separator from the positive electrode to the negative electrode.
What circumstances can LiFePO4 Batteries be charged normally?
For the charging environment of LiFePO4 batteries, the most important thing we need to care about is temperature. LiFePO4 batteries can be safely charged between 0°C ~ 45°C (32°F ~113°F), and do not require any additional equipment to ensure the normal charging process. Of course, this premise is that your LiFePO4 battery is already equipped with an excellent BMS, which can monitor the battery’s condition to prevent overcharge, over-discharge, and over-current.
Due to the nature of lithium batteries, LiFePO4 batteries cannot be charged normally at temperatures below 0°C (32°F) and must rely on some external devices to support charging, such as some heating elements. In winter, if you do not need to use the battery, it is highly recommended to do battery winterize, which can ensure that your battery can survive the severe cold. In addition, in the case of relatively high temperatures, LiFePO4 batteries can still maintain a stable state of charge without problems.
In addition to the temperature requirements, air humidity and the surrounding environment are also what we need to pay extra attention to. Excessive humidity and a complex environment are not suitable for LiFePO4 battery charging, which may cause battery damage.
What is a LiFePO4 Battery Charger?
LiFePO4 battery charger is a safe and efficient charger specially designed for LiFePO4 batteries. Since the nominal voltage of the LiFePO4 battery is 3.2V, the voltage of the dedicated charger will be above 3.65V, but the most popular one is the It is called a 12V charger. Similarly, in order to meet the needs of different voltage systems, chargers with larger voltages also exist.
The LiFePO4 battery charger adopts the CCCV charging method, that is, the charging mode of constant current and then constant voltage. This charging mode is more friendly to LiFePO4 batteries and can be fully charged faster. Take a single 3.2V LiFePO4 battery as an example, 3.7V~4V is the upper limit of the voltage, and a normal LiFePO4 battery charger will stop boosting the voltage at about 3.65V, and fill the battery with the remaining power at a constant voltage.
I have a charger for lead-acid batteries, do I still need to buy a LiFePO4 Battery Charger?
Generally speaking, since LiFePO4 batteries are often used as an upgrade project for lead-acid batteries, what we cannot ignore is that the voltage of a single lead-acid battery is 2V, while that of a single LiFePO4 battery cell is 3.2V. It is worth mentioning that the logic of lead-acid battery chargers is not the same, and lead-acid battery charging will have a floating charge stage. Since the voltage of LiFePO4 batteries will be higher, the lead-acid battery charger may identify errors and end the normal charging phase prematurely, which will result in LiFePO4 batteries not being fully charged.
So, can LiFePO4 batteries use lead-acid battery chargers? Theoretically possible, but not recommended. Because the effect is not as good as a special charger, and the connection between the lead-acid battery charger and the lead-acid battery charger needs to be cut off in time after charging, otherwise problems may occur. And if the BMS is not working properly, there is a risk of battery damage. Therefore, for safety reasons, it is not recommended to use lead-acid battery chargers.
Will cheap LiFePO4 Battery Chargers works?
It works, but this is highly not recommended. There are many reasons for the low price. It may be due to poor materials, lack of manufacturing process, confusion of charger parameters… Of course, it is not ruled out that it is a manufacturer’s promotion, but this possibility is too low. The price of LiFePO4 batteries is definitely not cheap, there is no need to risk using cheap chargers.
Can a higher voltage charger be used for LiFePO4 Battery Charging?
This is not allowed. The voltage of the charger can only be slightly higher than that of the battery. If the charging voltage is too high, the load of the battery will increase. The less harmful ones will affect the battery life, and the more serious ones will cause the internal burning of the battery. Therefore, when choosing a charger, you need to take it seriously. When necessary, you can ask the battery manufacturer and electrician’s opinion, and don’t blindly choose a charger. However, in the vast majority of cases, the BMS will prevent charging, so there is no need to worry too much about the safety of the battery.
Can solar chargers as well as alternators do LiFePO4 Battery Charging?
LiFePO4 batteries can be charged from many sources, which can be the grid, solar/wind, or alternators. However, it should be noted that different sources of electricity need to use different chargers to charge the battery, otherwise it will not be able to charge.
Summary
LiFePO4 battery charging is an important task. Although LiFePO4 battery charging is a relatively automated process, only when we understand the relevant knowledge can we ensure that there is no problem in the charging process, and we can make better use of LiFePO4 batteries. As a result, our lives will become more convenient.