We replaced our Blue Sky controller (after the second one failed - two failures in two years... not good) with Victron Energy controllers and have been using them for two years now. They are GREAT! We're getting more power out of the panels
than we ever did before.
The Victron controllers say their "fast" MPPT
controllers. I thought that was probably just sales hype but after seeing their performance, I think there must be something to it. I mainly notice the difference in lower light conditions like mornings, evenings, or with cloud cover.
Since installing them two years ago, I have not touched them. I often had to reset the Blue Sky controller, maybe once a month, when they'd hang. The HF radio
would often hang the Blue Sky controllers, even hanging the replacement that was supposed to be more RF tolerant. (It's never been a problem for the Victron controllers.)
As I remember, the Victron controllers model numbers represent the max voltage/max amps. I bought two (for two banks of panels) so I'd have redundancy and if one failed, I could switch the surviving controller to the highest output panels. So far, this has proven unnecessary.
I also bought the PC programming tool for about $75 USD, as I recall
. This also has proven unnecessary as the company I bought them from offered to set up the programming as I wanted it. I have not had to use the tool since installation
I know it sounds like I work for Victron but I don't. I'm just really thrilled to find such a great product!