It is my first post. I had some lifepo4 batteries from my old electric bicycle, so I decided to make a powerbank from them. For my project I used 56 3.3v 3A 26650 lifepo4 batteries. Every battery has 10w capacity, and the powerbank will have 560w in total. It is a big amount of energy to run electronic equipment in nature or use as a back up powerbank. I live on the boat, so it's nice to have some back up battery on board.
What we will need for this project:
- Plywood 7mm for box case (can be different thickness, but later dimension will be different)
- Lifepo4 3.2v 3000mah 26650 56 batteries
- 12V car sockets
- some cables
- wood glue
- Battery protection board 4S 7A 12.8V lifepo4 BMS PCM
- Blade Fuse holder
- Fuse 10A
- 2x binding posts
- Rope for handle
Step 1: Making a Box for Powerbank
You need cut 7 rectangles from 7mm plywood: 319x212mm, 335x89mm x 2, 212x86mm x 2, 212x79mm, 335x228mm.
After glue them together and twist with screw.
Step 2: Electric Circuit
We need to solder 4 battery cells. In every cell there should be 14 batteries.
Step 3: Almost Done!
Make holes for 12v car socket and for the binding posts. Connect everything together / and you will have the power bank. I use 4A car charger to recharge the batteries. It would be nice to have bigger BMS, but i used what i had at home. Now i am working on Monitoring battery status with esp8266 , but i will post this project later. I use this battery for my mobile portable refrigerator, and it can hold cool food for 3 days.