Regarding the battery issue, I had the same thing, as well as problems with the battery not charging at all at points. There are a bunch of threads on this forum with more details and solutions, I think I used this approach: Extremely Slow Battery Charging
In terms of build quality, I felt the quality was pretty good given the cost of the unit, I expected some trade offs and the ones made seem sensible to me. I think the tension in the rear support may be intentional, so it holds in place (though I removed the securing screw because it was too much force to hook and unhook it). But I might be less perceptive about manufacturing and design…