Combining solar panels to single LiFePo4 battery bank

[chrisblessing]

Greetings. I have completed the installation of a 160 watt flexible panel on the roof of my Scamp camper, connected to an MPPT charge controller and 120Ah LiFePo4 battery bank. Given the drawbacks of using a fixed panel in inclement weather or shaded spots, I'm wondering about the possibility of also connecting a 120 watt folding panel to my battery bank. This panel has it's own PWM controller and is rated at about 12v output, as opposed to the 18v of the fixed panel.

As far as I can determine, the most simple way to use the folding panel is to simply connect it directly to the battery bank in conjunction with the fixed panel and charger. Before attempting this, I'd appreciate some input from others.

Thank you.

 

[jasonhc73]

Why can't you put the second panel parallel?

 

[chrisblessing]

Why can't you put the second panel parallel?

Thanks jasonhc73. I did consider parallel, but there are efficiency costs involved given both the current and voltage differences of each panel. Furthermore, I anticipate only using the folding panel when necessary. The fixed setup generally does a fine job of keeping up with my needs.

The fixed panel uses an MPPT charger, and the folding panel has its own PWM charger, and my reading elsewhere indicates that there won't be any serious ramifications in simply connecting the folding panel directly to the battery bank.

My question here is primarily to seek any cautionary advice before attempting this.

Thanks again.

 

[jasonhc73]

The only thing that I know of having the panel directly to the battery, is when there is no sun out. There is a possibility to actually drain the battery with a panel that does not have diodes built in.