3s 18650 12V Li-ion Battery

I wanted to have a cheap Lipo 12V battery for my water pump. I decided to make my own by using

• 3x 18650 li-ion batteries
• 1x 12V PCB
• 3x 18650 battery holder

In addition, I used a Leatherman, soldering iron and solder, duct tape and a JST plug.

• Put the 18650 battery in the battery box
• Make sure that you set them in correctly - check polarity!
• You will need 3x 18650 battery boxes.

Do not mix the good battery and poor battery to use!

• Now you need to solder the batteries to the PCB
• Black wire is ground/negative, red wire is plus power.
• Keep strictly to the diagram wiring: 0V/4.2V/8.4V/12.6V,Otherwise it will cause damage to the chip!

• Solder a connector plug to the output of the PCB. I used a JST connector. However, you are free to use other connectors like XT60.
• Now the battery is working. If you like you can use duct tape like me to keep the 18650 boxes and the PCB together.
• I use the battery to power a 12V water pump.