Hoverboard fires continue.<p>Underwriters&#x27; Laboratories has now announced 1) that as of Feb 2, they have a test program to certify hoverboards for not catching on fire or blowing up, and 2), all UL labels on hoverboards so far are fake.<p>Amazon is refusing to pay hoverboard manufacturers for their products, and is taking returns on all hoverboards.  The hoverboard industry in Shentzen has collapsed.[1]<p>There are still daily hoverboard fire news stories.<p>Good technical analysis is rare so far. However, so far, the following have been reported:<p>- Fake Samsung batteries<p>- Batteries without cell-level protective devices<p>- Battery pack mismatched to charger, causing overcharging.<p>It takes about seven protective devices to make a lithium-ion battery safe. Some cells come with a small round circuit board at the end of the cell to provide protection and thermal monitoring at the cell level.  Some don&#x27;t.  Some cells have overpressure vents. Some don&#x27;t. Some have thermal fuses.  Some don&#x27;t. Chargers need to follow a charge curve, monitor cell temperature, and have a backup cutoff circuit to stop overcharging.  (If you overcharge a LiIon cell, it <i>will</i> catch fire unless some safety device trips first.)<p>This may be the worst product launch in modern history.<p>And these things aren&#x27;t even Internet-connected.<p>[1] <a href="http:&#x2F;&#x2F;qz.com&#x2F;582542&#x2F;chinas-makeshift-hoverboard-industry-is-imploding-after-amazons-safety-crackdown&#x2F;" rel="nofollow">http:&#x2F;&#x2F;qz.com&#x2F;582542&#x2F;chinas-makeshift-hoverboard-industry-is...</a>