Suitcase Solar: Location of Controller?

[blacklab]

Most, not all, Suitcase Solar kits I've read about have the Controller attached to the back of the Solar Panels. Thus, depending on whether or not you use an extended wiring setup, the Solar Panel + Controller can be 10' to 20' away from the connection to the RV's battery (via 7-pin, alligator clips to battery, etc.).

I've also read that it is best to have the Controller as close as possible to the battery.

Some Solar Suitcase kits are available without the Controller. In which case you'd purchase a Controller and, therefore, could locate it as close as possible to the battery, rather than on the back of the Solar Panel.

My question: Assuming a 15' to 20' wire run (appropriately sized wire) from the RV to the Solar Panel to allow finding the "best sun", what are the performance issues of having the Controller attached to the back of the Solar Panel compared to having it located, for example, right near the RV tongue where it attaches to the 7-pin umbilical cord?

Thank you.

Cheers,

Bryan

[ROBERT CROSS]

I have used my 15' extension.(30' total) on two Zamp 180w panels where both controllers are on the panels and charging thru the 7pin...no problem so far. 👍
POI...It was done as a test for 2hrs.

What is the expressed benefit of the proximity recommendation?

Bob
🇺🇸

[blacklab]

Bob,

Thanks.

The benefit(s) described were that it provides a stronger, more direct (i.e. less wire run between the Controller and the Battery), responsive connection with the Battery, allowing the Controller to respond to the feedback from the Battery more efficiently.

Certainly not my area of expertise, just been reading.

I can't recall where, but one technical writer said that locating the Controller on the back of a Suitcase Solar is the "worst" possible place to put it, because it is the furtherest away from the Battery in that location.

Cheers,
Bryan

[pdavitt]

Another benefit of having a separate charge controller, mounted near the battery is the expansion flexibility. If your panels (fixed and/or portable) have nearly the same voltage specifications you can wire them all to the same charge controller, assuming it is sized properly.
Pat

[uncle_bob]

Hi

Balancing all the solar panels into a single controller is a very iffy proposition. Running them into separate controllers is also a bit wonky in some situations. If indeed all the panels are from the same outfit / same model then you have a chance of hooking them up together. If that's not the case .... not a great idea.

Bob

[ROBERT CROSS]

We run two Zamp panels, each with a controller, into one charge wire.
The only charge anomaly we ran into was synchronization.

At the beginning I would plug each panel into the charge line as I set them up. Sometimes 5-10min apart.
Not good...each panel had it's own beginning SOC.

I now connect both to the single charge line and only then plug into the 7pin umbilical. They now reach 100% at the same time.👍

Bob
🇺🇸

[amaier7771]

Colonial Airstream installed a Zamp solar controller for roof mounted solar panels. They also installed provision to use a suitcase Zamp Solar panel. They ordered a Zamp Suitcase without a controller, but with a long cable and correct connector to simply plug in when needed.

The set up works great, the controller is close to the batteries, the Zamp controller accurately displays total charge rate and battery voltage regardless of only using the roof mounted panels, or roof and suitcase together.

90% of the time the roof mounted panels are adequate to keep the batteries charged, but on cloudy days or when under trees, the suitcase does the job.

Also, we measured the wall space in the 25FB FC closet and ordered the largest suitcase which would fit neatly in there against the bulkhead. This avoided a storage problem for the suitcase, and only takes up about 3” of space normally used for clothes on hangers. .

[GammaDog]

I have a 200 Watt suitcase using 2 100 watt Renogy panels and their Wanderer controller. I added an Anderson Power 50 Amp disconnect to the battery bank of the trailer. The connector is mounted to the battery box itself on the outside with 8” or so lengths of 6ga stranded copper. The controller has 8” 10 ga copper to the matching Anderson connector. The Wanderer has round magnets bolted to its mounting lugs. It is connected to the panels with 20’ Renogy cables. I carry an extra 10 cable set to extend the panels to better sun but I’ve never needed them. In use the magnets hold the controller to the A frame (in a plastic bag if rain threatens), less than 2’ of copper connect the controller output to the batteries through the Anderson connectors.

Works well for me!

I also use the Anderson to tie in a third Interstate group 24 if I need more amp hours. It could also be an output for 12 v appliances (fan, light, etc.) if needed.