Voltage Step-up and step-down of lithium batteries

Voltage Step-up and step-down of lithium batteries

1. Test

Test Process:  Lithium battery voltage step-up and step-down test. First, let the voltage of the lithium battery through step-down chip down to 3.3 V, and then to the MCU and Bluetooth module power supply, and plan to rise to 7V to take a load. 

Results:  the Bluetooth module does not work and is not searchable. Remove Bluetooth, MCU and load are normal work. When the monolithic integrated circuit is removed, the Bluetooth works normally with the load. When a group of power supply is provided alone, all three work normally without using step-down voltage. 

Remark: Set down XC6206(Low ESR Cap.Compatible positive Voltage regulators), step-up FD6291.( Step-up Current Mode PWM Converter)

2, lithium battery step-up and step-down problem---below to analyze the reasons for the above problems:

To find the lithium battery step-up and step-down common problems, learn together. For example, a Lithium thionyl chloride battery ( LiSOCL2 battery ) have a operate voltage of 2.0-3.6 V, a lithium-manganese battery ( LiMNO2 Battery ) at 2.0-3.0 V, and a lithium-polymer battery ( Lipo battery ) at 2.75-3.7 V, the normal operating voltage range of lithium iron phosphate battery is 2.5 v-3.65 V, and that of lithium manganate and ternary battery is 3v-4.2 V. Battery protection board are required when the total voltage of the lithium-ion battery is 60V or below. Battery Management System (BMS) is required when the voltage is over 60V. The function of these two devices is to protect the battery to work properly. 

Note that you can not adjust the battery voltage at will after the series number is set. That is, the battery voltage changes only in the normal range of working voltage changes: charging, from the lower voltage to the upper voltage limit. When using electricity, from the upper limit of the voltage down to the lower limit of the voltage. Understand this problem, if you want to make lithium battery voltage range is large, can be adjusted at will. The Best Solution: Make a group of batteries, with a suitable inverter, and then with a DC voltage regulator, can meet the lithium-ion battery step-up and step-down requirements. 

Summary: 

This method is rarely used in practical applications, unless the AC power used is often out of power, or solar or wind power to charge the battery pack, will only consider this method of boosting and reducing voltage. 

The above lithium battery step-up and step-down methods, can be used in the test, used to study the learning effect is good.