Portable solar suitcase

[Capt Dave]

Hi Everyone. I have a 100 watt Renogy solar suitcase. How do I test its output? When I hook it up to my two 6 volt batteries hooked in series it will only get to a max 12.4 volts and never register higher. I have left it in full sun for hours and it never charges above 12.4 volts. My batteries will fully charge to 12.7+ when generator is used or on shore power. Is there a way to test the solar panels output? I do own a multimeter but am not very well versed in how to use it. Any detailed instructions would be greatly appreciated
Thanks

[SeaDog]

Make sure you have the controller set to the correct type of battery I made that mistake on my Renogy 200 after putting it to the correct type it charged correctly. Just something to check.

[Hclarkx]

My thoughts ........

Your suitcase has the Voyager Charge controller, right?

Does your voltmeter agree with the LCD display in the Voyager?

Do you see a rising voltage before voltage stops rising at 12.4V?

At what time of the day are you seeing 12.4V?

Does the "System Status" icon on the Voyager make sense? Does it indicate active charging is occurring? And, of course, there is no error code showing?