The problem is that, in a lot of cases, there&#x27;s little QC on the third-party batteries, or even necessarily ways to validate the battery, since they&#x27;re all just going to be using one of a handful of &quot;copied&quot; chips.<p>Then you get into fun with who&#x27;s liable if a battery explodes - many of these vendors don&#x27;t really have much concrete existence, and good luck with a &quot;warranty&quot;.<p>Source: tried playing hard and fast with batteries a few times, including helping someone solder his own cells into a dead first-party battery.