A few weeks ago, my boss lost his new construction farm house & a truck in a house fire. He told me that the fire inspector said the fire started in the garage and was caused by a Kobalt lithium ion battery exploding. Inspector says he's seen it happening frequently with Kobalt batteries. Make sure you're storing them in a firesafe box & don't leave them attached to their tools or leave them unattended while charging. Kobalt is coming to his farm to calculate/assess his losses.