I think I know the answer to this question, but: I finally broke down and got a Hitec x4 charger, and it’s the single best purchase I’ve made in this hobby–I fly so much more now that I can quickly and accurately charge my 1S lipos. However, around half of my lipos–including some nicer ones with only a few cycles in them–only last 10-15 seconds of flight time. When I plug them in, they’re still at 4.18 or something close to it. Is it the connector? Did I damage them with my stupid USB charging?
A couple of my brand-new batteries that I’ve only carefully charged get 2 minutes or so, but that’s the absolute limit. It’s mildly infuriating.
I’m tempted to just toss all 12+ lipos and get a set of the JST 2.0 ones.