Review on Efficient 20A Solar Charge Controller with Adjustable LCD Display for 12V/24V Solar Panel Battery System, Intelligent Regulator featuring Dual USB Ports by Steven Stager

As you know, the role of the solar controller is to regulate everything between the panels and the battery. When the battery reaches the controller's "pre-programmed" cut-off voltage, it is assumed that the connection between the solar panel and the battery is broken. For example, I have an AGM Deep Cycle battery and the solar controller is programmed to slow the charge rate after the battery reaches 13.7 volts. Well, the only time I relax is charging my laptop with the inverter when the inverter goes into "failure" mode. For a few minutes I thought it was a bad inverter until I checked the battery voltage and was startled when it read 17.9 volts! Check the controller and it said the same thing and the icon showed the battery was NOT charging. Now I thought the battery was dead so I started taking the connections apart. (Battery is connected first and disconnected last). So the first step is to loosen the panels. As soon as I disconnected the connections on the panel, the regulator and voltmeter read 13.9 volts. I plugged the panel back in and it jumped to 17.9. This directly means that the CONTROLLER has failed. This allowed raw voltage to flow to the battery, overcharging the system. If I could give this cheap product 0 stars I would. Cheap useless crap, buyers BEWARE!