Just a cautionary video about my experience with BLS Batteries shipping used lithium iron phosphate cells despite advertising them as new. LiFePO4 cells are fabulous when new, for DIY solar and many other 12 V lead acid battery replacement purposes. New LiFePO4 cells have a typical lifespan of several thousand cycles, but used batteries can be pretty close to the end of their lifespan, depending on how much they were used before being resold. If you need to use the batteries long-term, it's better to find a different distributor since at least some of the time BLS batteries is shipping used cells instead of new.