We have done previous demos, showing the difference between a 20V (60 cell) and a 24V (72 cell) solar panel. What we want to show today is some real world usage of it; trying to use either of them to charge a 24V deep cycle battery bank.
A lot of people will call and say they’ve got a 60 cell solar panel and want to charge a 24 volt battery bank with it. Is this possible? Because when measuring it, they are getting say 38-39 volts out of it open circuit voltage, so shouldn’t that be plenty to charge a 24 volt battery bank? The problem is…heat. When it gets hot out, the voltage output of solar panels drops pretty dramatically.
See what happens when our Solar Queen attempts to charge a 24V battery with a 20V solar panel on a hot, summer day. And see how that compares to doing the same, using a 24V solar panel.