OK, so now I feel stupid, yeah I remember being told to make sure I got an MPPT charge controller way back when. So, I'm shopping for one now for this little system and I find that there's a number of really cheap ones and some really expensive ones and they all say they do exactly the same thing. But now I'm suspicious. I only need to handle about 40 V max input and about 10 amps max output. Got any recommendations?