Battery problems are what sent me back to using a KR808. Some scary stuff. I still feel as if the pv industry is in its infancy and more work needs to be done with regards to safety. I think the Provari, and to some extent the Darwin, have good safety features, but you use the other big battery mods (or stacked batts) at your own risk. What amazes me is the number of people on here who extoll the virtues of the Silver Bullet, which has no vent holes. So it is essentially a pipe bomb if something goes wrong. To each his/her own. 