I have read the web site for the Renogy Solar Suitcase and I have a number of thoughts I would like to share. First, it is hard to evaluate because they do not give the specifications on the two most critical parts: the solar controller they provide and the gauge of wire used.
The major design flaw, and this is common to numerous other similar portable products, is the distance from the solar controller to the battery
. Recommended distances are "as close as possible" or use very heavy gauge wire, 8 for example between the controller and the battery
. Distances should be kept to 3 feet or less would be my recommendation. Because they mount the "waterproof 10 amp controller" on the panel and provide 16 feet of unknown gauge wire with the recommendation not to use more wire, we see a red flag waving.
My second concern would be what voltages this controller is going to be putting out, especially with 16 feet of wire between. We do not know.
Wire gauge is of minor concern between the panel and the controller. Often time 14 gauge will allow runs of up to 100 feet. Gauge between the controller and battery is critical, as is the distance.
Could this be made into a functional unit? Possibly. You would need to remove the controller from the panel and place it next to your battery. I would use the Anderson Power Pole products to make the connections. I have successfully used a 100 foot 14 gauge extension cord. Simply purchase a male and female three way plug and add to your wiring. For short runs joint the plugs, for long runs add an extension cord of a desirable length. Can you tell what type of solar panel
it is? Monocrystalline or Polycrystalline, it would be nice to know.
Finally, I worry about the controller. For Interstate batteries the manufacturer recommends an absorption rate of 15.3. Trojan recommends a 14.8 absorption rate. There are very few solar controllers that can reach these recommendations. The Tristar unit that was mentioned above is one, an excellent controller and I do not think it is overkill. Check what your batteries recommend for an absorption rate, it should be available on their website. Because of the variety of brands your experience may vary.
If you want to take your solar knowledge to the next level I would recommend you try Handy Bob's Blog
. There is a wealth of information about solar, batteries, charging and wiring. A must read before spending $200+.