How to make a 12V battery pack using 18650 Li-ion batteries

18650 lithium battery is widely used due to its advantages such as high energy density and long life. Making a 12V battery pack usually requires combining multiple 18650 lithium-ion batteries in series and parallel to achieve the required voltage and capacity. The following are the steps and precautions for making a 12V battery pack:

Required materials:

1. 18650 lithium-ion battery: at least 3, rated voltage 3.7V.

2. Nickel strip: used to connect batteries.

3. Spot welder or electric soldering iron: used to weld nickel strips.

4. BMS (battery management system): used to protect the battery pack from overcharge, over discharge and short circuit.

5. Connecting wire: used to connect BMS and battery.

6. Heat shrink tube or battery: used to protect the battery pack.

7. Insulation tape: used to insulate and fix the battery.

Steps:

1. Design the battery pack configuration

-The rated voltage of each 18650 battery is 3.7V, so you need to connect 3 batteries in series (3S) to get a voltage of 12V (3.7V x 3 ≈ 11.1V, full charge voltage is 12.6V).

If you need a larger capacity, you can connect multiple 3S battery packs in parallel (for example, 3S2P configuration means 3 batteries in series, two groups in parallel).

2. Connect the batteries

Series: Connect the positive poles of 3 18650 batteries to the negative poles of the next battery, and so on. The final battery pack voltage is 3.7V x 3 ≈ 11.1V.

Parallel (optional): If you need to increase the battery capacity, you can connect multiple series battery packs in parallel, with the positive poles connected to the positive poles and the negative poles connected to the negative poles.

3. Install BMS

-The role of BMS is to protect the battery pack from overcharging, over-discharging and short circuits. According to the instructions of the BMS, connect it to the positive and negative poles of the battery pack and the connection points of each battery.

-Usually, the BMS will have clear markings (such as B+, B-, P+, P-, C+, C-), connect it correctly according to the markings.

4. Fix and protect the battery pack

Encapsulate the battery pack with heat shrink tubing or battery box to prevent external damage or short circuit.

Use insulating tape to fix the battery and connecting wires to ensure that the battery pack is stable and reliable.

5. Test the battery pack

After assembly, use a multimeter to test the voltage of the battery pack to ensure that it is between 11.1V and 12.6V.

Ensure that the BMS works properly and charging and discharging can proceed smoothly.

Precautions

When assembling 12V 18650 lithium batteries, special attention should be paid to the following matters:

Safety protection: During the welding process, pay attention to prevent battery short circuit and overheating to avoid fire or explosion accidents.

Correct connection: Ensure that the positive and negative poles of the battery are connected correctly to avoid reverse connection and battery damage.

Insulation treatment: After welding, be sure to insulate the welding part to avoid short circuit.

BMS function: When connecting BMS, ensure that it functions normally and can protect and manage the battery.

Testing: After assembly, be sure to test the battery pack, including capacity test, cycle life test, etc., to ensure that the battery performance meets the requirements.

Quality control

After assembly, strict quality control and inspection should be carried out to ensure the performance and safety of the battery pack. Establish a quality traceability system to record the data and test results of each link to discover and solve problems in a timely manner.

Environmental awareness

During the assembly process, pay attention to environmental awareness, reasonably handle waste, recycle resources, and reduce the impact on the environment.

Assembling 12V 18650 lithium batteries is a complex and critical process that requires strict control of every link to ensure the performance and safety of the battery. During the assembly process, special attention should be paid to safety protection, correct connection, insulation treatment and other matters to ensure assembly quality and production safety. Only by fully grasping every detail can high-quality and reliable 12V lithium battery packs be produced.

The above is the detailed steps and precautions for assembling 12V 18650 lithium battery. If you want to know more about 18650 lithium battery, you can contact our company: sales01@csit-energy.com