The upper limit of the charging voltage of a single lithium iron phosphate battery is 3.65V. Generally, the upper limit voltage of lithium iron phosphate battery charging is 3.7~4V, and the lower limit voltage of discharging is 2~2.5V. The voltage of lithium battery is one of the important indicators to measure the discharge performance of lithium battery. The unit is volts.

LiFePO4 battery voltage
Common 18650 batteries are divided into lithium-ion batteries and lithium iron phosphate batteries. The voltage of lithium ion battery is 3.7v nominal voltage, the charging cut-off voltage is 4.2v, the nominal voltage of lithium iron phosphate battery is 3.2V, the charging cut-off voltage is 3.6v, the capacity is usually 1200mAh-3000mAh, the common capacity is 2200mAh-2600mAh .

Why is the lithium iron phosphate battery voltage 3.2V?
Lithium iron phosphate battery refers to a lithium ion battery using lithium iron phosphate as a positive electrode material. The cathode materials of lithium-ion batteries mainly include lithium cobalt oxide, lithium manganate, lithium nickel oxide, ternary materials, lithium iron phosphate, etc. Among them, lithium cobalt oxide is the cathode material used in the vast majority of lithium-ion batteries.

The nominal voltage of the lithium iron phosphate battery is 3.2V, the high end charge voltage is 3.6V, and the low end discharge voltage is 2.0V. Due to the different quality and process of positive and negative electrode materials and electrolyte materials used by various manufacturers, there will be some differences in their performance.

3.2V lithium iron phosphate battery, which can be discharged in large capacity. Now all electric vehicles use this kind of battery. This kind of battery has a long life and light weight! 3.6V and 3.7V are the same as polymer lithium batteries. The upper limit of polymer lithium batteries is 4.2 and the lower limit is 2.6. The general standard is 3.7V.

The charging voltage of the lithium iron phosphate battery should be set at 3.65V and the nominal voltage is 3.2V. Generally, the maximum charging voltage can be higher than 20% of the nominal voltage, but if the voltage is too high, the battery may be damaged. The 3.6V voltage is lower than this indicator. Not overcharged. If the battery is set to a minimum of 3.0V, it needs to be charged, then 3.4V is 0.4V higher than the minimum, and 3.6 is 0.6V higher than the minimum. This 0.2V can release half of the power, which means that each charge is half more than 3.4V. Use time, because the battery is used for a certain number of times, the life is increased by half, so increasing the charging voltage will increase the battery life without damaging the battery.

The discharge platform of the lithium iron phosphate battery is: 3.2V
The discharge range is: 2.5-3.65V
This maximum charging value can be changed according to customer needs (protection board parameters)
Generally, the maximum charging voltage is set at 3.85V
When it reaches 3.85V, the protection voltage is reached, and the protection board will automatically cut off the charging circuit to protect the battery.

Li-ion battery voltage

The discharge platform of the lithium-ion battery refers to the voltage change state of the battery when the fully charged lithium battery is discharged. When the battery is discharged with constant current, the battery voltage has to go through three processes, namely, decrease, stabilize, and decrease again. Among these three processes, the stabilization period is the longest. The longer the stabilization time, the higher the discharge plateau of the battery. The level of the discharge platform is closely related to the battery manufacturing process. It is because the market positioning of each lithium battery manufacturer is different, the technical process is different, the discharge platform controlled by it is different, and the quality is also very different.

Generally speaking, a 18650 lithium battery has a full voltage of 4.2V, and when it is discharged to 3.7V with a 1C current for 60 minutes, then we say that the battery has a capacity of 2200mAh. Nominal voltage, also known as rated voltage, refers to the voltage exhibited by the battery during normal operation. The nominal voltage of lithium batteries is generally 3.7V or 3.6V.

Depending on the cathode material of the lithium battery, the nominal voltage will vary. The nominal voltage of lithium cobalt oxide battery is 3.7V; the nominal voltage of lithium manganate battery is 3.8V; the nominal voltage of lithium nickel cobalt manganese ternary material is only 3.5-3.6V, but with the continuous improvement of formula and structure Perfect, the nominal voltage of the lithium battery of this material can reach 3.7V; the nominal voltage of the lithium iron phosphate battery is the lowest, only 3.2V, but the lithium battery of this material is very safe, will not explode, and the cycle performance is very good and can reach 2000 week.

Lithium-ion batteries have high working voltage (three times that of nickel-cadmium batteries and nickel-hydrogen batteries), large specific energy (up to 165Wh/kg, three times that of nickel-hydrogen batteries), small size, light weight, long cycle life, and self- Low discharge rate, no memory effect, no pollution and many other advantages. Among lithium-ion batteries, lithium iron phosphate batteries are more promising. Although this battery has lower specific energy than lithium cobalt oxide batteries, it has high safety and large single battery capacity.

The above is the voltage of lithium iron phosphate battery and the voltage of lithium ion battery. When choosing a lithium battery charger, you should pay attention to the output voltage of the charger. The charging mode is constant current + constant voltage.