2021 Micro Minnie 2100BH Solar Upgrades?

[Texasprinter]

Howdy from Texas
I have 100 watt panel on the roof but I would like to add a plug where I can add a 400 watt foldable panel so I can move it around as needed. Will the existing controller handle 500 watts? Also where do I purchase the plug and wiring? I also have 2 100amp hour Lipo batteries.

[Marine359]

Do yourself a favor and don’t try to use one controller to service both the roof, and portable panels. The roof pv array should be routed through the rooftop MC4 gland. Those cables terminate in the pass through forward bulkhead on the curb side. You didn’t say what controller you have, but there needs to be a manual reset breaker between the pv array and the controller.

When installing portable solar, it’s best to install a second solar charge controller to service the portable panel(s). Easiest and inexpensive is a SAE port with as long of an inside cable lead as you can find. No fuse is needed because the port isn’t hot when the the portable panel is not connected. If you go this route, you’ll be able to place your panel 30ft away from the camper with virtually no voltage loss. And, rarely have we been in a campsite where 30ft of cable wouldn’t get our panels out from under canopy and into the sun.

Here’s what you’ll need for the project.
1. A mppt solar charge controller large enough to support the amount of incoming voltage from the portable panels. 75/15 controller serves well for most installs.
2. SAE port with longest possible inside cable lead of 10awg cable.
3. Tube of silicon sealant
4. MC4 to SAE harness. Buy the harness that comes with the polarity switching plug.

Drill a hole in the sidewall the correct size for the SAE plug. If you drill the hole as high as possible such that it still enters the pass thru, you can easily route cable wires across the pass thru rafters, and then down to the controller. Mount controller as close to battery as possible. Seal the SAE port into the hole with silicon sealant. The screws that come with the port will rust, so it’s best to replace them with stainless screws from the outset. If you’re going to use 2x 200w portable panels, wire them together in series. Series will double the voltage, but amperage remains the same. There will be less transmission loss, and higher controller efficiency when incoming voltage is maximized. And amperage is not increased. But series will suffer from shading. If one panel is partially shaded, the entire array efficiency will drop. Keep both panels in the sun.

Take a look at photos in my album which cover this subject pretty well. You can PM me if you like.