This build appears familiar... like I made a comment on the safety of one similar a while back...I was really proud of my DIY battery build with headway cells until I stupidly put a cardboard box on top of the batteries not paying attention to the hazard. One of the positive lug bolts pierced the thin film and the cell burst into flames. Fortunately my wife and I were close by and pulled out the burning box and batteries with only small injuries. IT COULD HAVE BURNED MY WHOLE SOLAR BARN DOWN TO THE GROUND!! I took for granted how safe LiFePO2 battery chemistry was and it almost cost me dearly. Attached are photos of the completed battery and the burned batteries (3 total out of my 12 batteries). Note that I’ve circled the lug bolt in yellow to show the source of the error. PLEASE learn from my mistake and consider all battery chemistries hazardous for your DIY project.