Here is video that covers the construction of lithium batteries. This guy is one of a few places that build batteries in the USA. I believe the outfit is called the Mad Scientist out of Flora Mississippi. He goes over what goes into building lithium batteries. I remember him saying condensation is the main reason batteries fail. He also mentioned a quality BMS is also important and does name the two he uses. He provides some good information. The cool thing is they repair batteries while you wait
The Baddest Lithium Batteries On The Market!!! - YouTube