DIY 12V High-Performance Outdoor Power Supply is a practical 12V outdoor power supply using 18650 ternary lithium batteries. Due to space constraints in the battery compartment, we will use a total of 36 18650 ternary lithium batteries, divided into two groups. Each group will be assembled in a 3S6P configuration and then connected in parallel for use.
Before assembling the cells, it’s essential to perform capacity sorting to ensure high consistency in capacity and internal resistance. This step maximizes the performance of the entire battery pack and minimizes any negative impact.
We have chosen cells with a capacity of 2 Ah. The entire battery pack will use a 3S12P configuration, resulting in a total capacity of 24 Ah, a total voltage of 12V, and an energy storage capacity of approximately 0.28 kWh. This is sufficient to meet basic outdoor power needs.
For the protection board, we will use a 3S 18650 ternary lithium battery-specific protection board with a current of 40A and a maximum discharge rate of 5C. With a 24 Ah capacity, the maximum discharge capacity can reach 100A, providing strong support for stable power output.
When connecting the protection board, the negative terminal should be connected to the total negative of the battery, the 4.2V terminal to the positive of the first series battery, the 8.4V terminal to the positive of the second series battery, and the 12.6V terminal to the total positive of the battery. After making these connections, you can check if the protection board has an output voltage to determine if the installation is complete.
Follow the same steps to connect the second group of batteries using nickel strips.
Next, connect the two battery groups in parallel. Place insulating materials such as kraft paper or epoxy board between the electrodes of the two battery groups. Then, use high-temperature double-sided tape to fix them in place. Once fixed, use nickel strips to connect the two battery groups in parallel.
After completing the parallel connection of the battery pack, remember to apply high-temperature tape to strengthen the fixation and insulation further.
Install the finished battery pack into the battery case. Connect two wires to the output end of the protection board: a thinner one for the charging line and a thicker one for the discharge line, which will connect to the load.
Finally, install an 800W inverter to the battery pack. At this point, a compact outdoor power supply is ready. It can easily power 220V electrical appliances outdoors, adding great convenience to your outdoor adventures.