Epever makes several different models of controller, mostly for use in larger home solar arrays. All of them
are MPPT, and they come in a variety of maximum voltage and current. They're also designed to work remotely,
using a control head that displays current information as well as letting you make changes to how the
controller is behaving.
Carefully consider your solar panel production when picking a controller. Make sure you get a controller with
a Vmax safely above the Voc of the panels, adding them if they are in series. Make sure the current from the
panels and the draw your load will produce are both below the Imax of the controller. This needs to include
the amps produced when transferring the panels' maximum watts at the battery's bulk charge voltage.
As an example, 8 panels can produce 600w. If I'm trying to charge a battery at 13.8v, the controller will
deliver up to 43 amps to the battery, which is actually a little over its limit. The 8 panels in two parallel
groups of 4 in series, deliver about 60 volts at 10 amps, but the voltage goes up near 90v with no load, which
is just under the controller's 100v limit.
This controller has a few drawbacks - its built-in display is pretty basic, so you have to attach the remote to
it to get more information, and the remote doesn't display watts or count up watt-hours. So I usually attach
one of my deluxe inline meters at the panel input so I can monitor power and total energy production. So be
sure to get the remote. Standby current is surprisingly low, at only 29mA.
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