Low profile bullets, for battery leads, have become a headache for some of my LiPo packs. In some cases, the four pronged (that's what I call them anyways) low profile bullets
fit fine in the battery, other times they are a tight fit, or a little loose. The tolerances in the batteries 4mm tubes are not so great, and is why I'm having a hard time with them. I'm going back to the birdcage style of bullets.