Just got the 1kw Kool Energy lithium unit yesterday... charged for 8 hours but it got stuck at 56%, then I came and found this thread. Trying a full discharge and recharge now to see if that helps.
Aside from battery issues though, my unit seems to make quite an audible fan... buzz? Not sure how to describe it, but it's a low hum in addition to just the sound of the fans spinning, and it's constant whether charging or not - is that normal or did I get a dodgy unit?