What voltage is your system, and how much installed PV capacity?
One thing I've found out about solar controllers is that you tend to never buy one that's big enough. A lot of people have a tendency to try to save a dime now so you can spent a dollar later. So you always got one for sale every time you add some panels because you need a bigger, or another, one. I'm not using this one on solar - got it on my wind turbine - but this is the "Cadillac".
It'll scale from a "starter" PV array to 2.5 kW or so. You can't blow it up on a cold day by wiring your panels at Voc close to its voltage input limit, it logs data for 380 days, and if you hook up an ethernet cable from its ethernet jack to your home router you can use the nice desktop application for it that shows how your system is performing from the comfort of your office:
I've spent a small fortune on solar controllers every time I add more panels. I got two Morningstar TS-MPPT's and they're both going to be replaced soon with one of the above units.
I would've spent less money if I would've bought one of the above units in the first place. Just from here.
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Chris