I've written a reply to your post travellerw and Ed but I am new to the forum and have just realized that using any hyperlinks or images
requires moderator approval so
I guess we will have to wait a few hours on that one but it includes a link to my current BOM.
Ex-Calif, I'm interested in all comments and my main goal is nearly hobbyist in the sense that I just want to do it on principle. If I can make a small profit off of it while also putting a decent controller in peoples hands well that's great too, every little bit helps when you are boat broke.
I'm sure the more expensive name brand controllers are great and all but as many have pointed out you can often just spend the money
on an additional panel and come out ahead once you consider the price of the controller. Of course this doesn't work when you start running out of deck
space and hence the need for MPPT arises.
As for the market being crowded at the low end, it is and it isn't. Most have reported the vast majority of chinese charge controllers to be complete junk. Lying about their functionality or outright not working. Short of the single
model I mentioned in my first post that travellerw has confirmed as being of acceptable quality there really isn't much else out there workable under the $200 range.
Regarding bells and whistles, they can often be added at the cost of development time and not really any significant hardware
cost. I have a nice little software
library I've compiled from my own and open source code to do wireless communication with less than 3$ of components. This in combination with a laptop
or even a small standalone lcd display could grant you a myriad of features especially once you consider it will all be open source and free for anyone to add to or modify.