There’s lots of comments on many drone forums about this topic. They can and do fail. Search this forum regarding battery tips, and follow them religiously. I’ve had 3 XSP batteries suddenly go flat in the air. Once it was Autel’s fault, I lost the drone, they replaced it. The other two could have been my fault, not taking enough care in cycling them properly. Also, only fly with fully-charged batteries, even if you must top them off if you couldn’t fly the day you planned to fly. Stuff happens, batteries sit for a few days. They start to discharge themselves for their long-term health. Luckily the other two times it was close to me, easy to retrieve. I now keep a log of each battery, and I haven’t had a problem since....