Charging a 24V Battery with 20V Solar Panel & PWM Charge Controller

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.

Can I charge a 24V battery with a 20V Solar Panel?

About Author

Amy Beaudet
Amy Beaudet has been in the solar industry at the altE Store since 2007. She’s been a sales rep, an instructor, and an all around solar evangelist, sharing her passion for solar around the world. When not at work, she’s either sailing or skiing, depending on the season, but odds are good she’s still talking about solar on the boat or on the slopes. See more of Amy Beaudet's blog posts.