I saw your video and agree with Sean. I am not sure what you were expecting but I would expect exactly what you showed in your video. I would recommend plugging your LiPo back into one of those chargers and allow it to charge fully. I think your charger lights will go all green when all the cells are at maximum capacity. At that time, if you check your total voltage it should be 8.4VDC or very close to it.
Let us know how it goes.