Morningstar Prostar 15A PWM Solar Charge Controller 12V/24V - Reliable Battery Regulator for Solar Panels | Low Failure Rate | Perfect for RV, Boat, Off-Grid & Home Solar Systems

Review of the Morningstar Prostar PS-30M PWM Solar Charge Controller - I bought my Prostar 30M controller about 3 years ago. At first I only used it for some limited solar panel experiments with a couple of marine batteries and it worked well. In March 2018 (2 months ago) I finally installed it on my plywood solar controller board for my 400 watt system along with some 12 volt timers to use with inside/outside lights, fans, and other devices. I’m using Duracell GC2 Golf Cart Batteries in my design. This controller works with either 12 or 24 volt solar systems.During these two months the PS30 has operated through a temperature range of the upper 20s to about 92 degrees Fahrenheit and operated flawlessly. In my design I do have a small Noctura cooling fan blowing on the heat sink side of the controller. I like the flexibility of selecting the battery type connected to the PS30 (SLA, AGM, FLOODED). The physical meter alternates showing the battery voltage, charging current, and load current. It also has a Low Voltage Disconnect feature built in to avoid draining the batteries below a predetermined voltage level.I’ve been very pleased with my experience with the PS30 except for one annoyance. There is a noise, a hum or buzz sound generated by the PS30 which I’m guessing is caused by the Pulse Width Modulated PWM operation of the unit. From what I’ve read, Morningstar says this is normal. It does not seems to cause any problems in my connected 12 volt radio, but a wired voltage regulator circuit seems to hum or buzz in unison with the controller. But to be clear the PS30 seems to be working correctly in every way.Morningstar builds quality products from everything I’ve read and observed. The PS30 cost more than other available controllers on the market, but it is American made. It’s working well for me.