BZ Products MPPT500 MPPT Charge Controller, 42A, 12/24/48 VDC

The MPPT500 is a great charge controller for a stand alone solar panel system. It is one of the few that not only boosts the current going into the batteries but also will fully top off the batteries without overcharging and boiling them off. Other charge controllers that have MPPT and Absolute float voltage control that gradually reduces the current as the batteries top off cost twice as much per watt and don't come with the 5 year warrantee. I have 1600 watts being controlled by four (4) MPPT500 units from a mix of different size panels running either a 2 panel series/Parallel or a 3 panel series/parallel (24 volt(35 volt)/36 volt (47 volt)) of 12 volt panels (nominal 17.6 volt outputs each) and the MPPT coverts the voltage automatically to the 12 volt RV type system I have and boosts the current by taking the extra 3 volts over the 14.6 needed and converting the raw power to more amps to the batteries. Other shunt type charge controllers can not convert. They just shunt the panels and disconnect the battery when the average voltage goes above 14.1 Volts and that happens when the batteries are only 70% full. MY four MPPT500 units are used parallel and do not interfere with each other so the only limit to how much wattage you want to use is the Number of MPPT Units you wish to connect to the batteries and the total watts of panels you install. I limit the input at 420 watts each system to reduce the heat the charge controller produces. My fist unit failed after 4 years when the plastic screws that heat sink the diodes melted and fell to the bottom of the controller's box and they lost their heat sink. BZ products replaced the unit and they told me to series the panels instead of paralleling all the 12 volt panels because that reduces the input current that causes part of the heat. They run better when the input is closer to 48 volts.