Well, that's a thing I know now...

For a number of years now I have whined about off brand EC5s not going together right. I don't know how I got there, but I read a thread about EC5 gripes on one of the rc groups, and someone commented that the off brands often go in backwards from the Horizon Hobby originals, that is, you don't press them through the back, you instead rub the wires through the plastic, solder them, then pull them back through the front.

I just got two new batteries, so tonight I did that and they went together simply...

Damn.