I bought 12 of the 250mah 1s hvlipos from newbeedrone and they were awesome. I flew them around maybe 20 cycles each so far over the last 6 months and have kept them stored truthfully around 3.65-3.8v when not using them. Which I'm not totally sure if being closer to 3.6 is really bad to store for weeks at a time? But mostly they were like 3.75ish.

So on to the problem.. I current tested my tinywhoop motors in motors tab and at full throttle each is drawing ~1.4amps. So that's like 23c and these batteries say they rated 30/60c. But when I even give 50% throttle, the voltage will drop from 4.2v down to 3.5v and sometimes below 3.3v. That's nuts, are these batteries bad already?

My thoughts: If you tested with props off, then motors may not draw nearly as much as your motors with props on.

Also, if you have 240 flights on those motors, they could be the problem - especially under load.

Tested with props on always. I've replaced the motors a few times but I broke the frame a little bit after getting my last set of motors so I haven't flown them very much yet so they should be good.

A short working life seems to be a feature that all the high voltage LiPo batteries have in common.