In my quest to find cheap options for my electric vehicle batteries I came across these nice little hard plastic case battery holders. My plan is to gang together as many of these as needed for my various off highway vehicles. In this video I show how to build a 21 amp hour 12 volt lithium battery using 18650 cells. Nice little water proof case, nickel strips, and BMS board are all included for just $5. You may want to use thicker nickel strips if your going to be pulling high amps. I added a balancing connector so I can verify the BMS board is working.