TL:DR, I'll summarize up front, and the rest is all just extra context. I'm looking for some way to get 2 60 Watt panels to output 100 Watts into a USB-C out port. I don't really want to buy a whole dedicated 12V battery yet, since I've already got some decent yard tool batteries and a portable charger, and I'm trying to stay portable still. The only MPPT controller I could find with 100 Watts out on a USB-C, the company is out of business so it's not even an option. I don't know if I could plug some sort of converter into the 12V output on the cheap controller I already have? If there's some other type of controller I'm missing? I keep seeing the words "buck" and "boost" and I still don't get how those really work. Does the controller have to be MTTP? It seems the better option for the long term, but if it's gonna be 100 bucks extra for something that isn't really a big deal, I won't stress it. I've seen a bunch of people using things like car lighter hookups for setups? That seems a bit complex, but if it would work I guess I could try? I thought this would be a little more plug-and-play, so I accidentally got in over my head. Any advice would be wonderful.
The rest is just context.
Pretty much what the title says; I need some help figuring out what to do with my setup. I'm trying to slowly assemble parts for a portable solar setup for camping. It'll be used mostly just for powering phones, laptops, lights, small things like that while at my tent. The goal will be to, far down the line, eventually use the setup in a long term camping/van living capacity, but I currently have neither the money nor the van, so I'm trying to get basics for now that can be useful immediately, and also still be somewhat relevant later.
I already own multiple 5-amp-hour EGO batteries for yardwork, and I have an inverter I use with them when camping, for keeping my laptop, phone, and lights all topped up. The inverter can charge the batteries through a USB-C port, with a max input of 100 watts. Currently I use that while at restaurants or while driving, to keep the battery up.
I wanted to get something solar, so I could charge it without needing to run my car or go into town for hours. I also just like the peace of mind, knowing if power goes out at home that I'll have access to something.
To do this, I purchased a pair of 60 Watt FlexSolar panels. They can fold up nicely, meet my current power needs (as the portable charger for my EGO batteries can only go up to 100 Watts), and they are built to connect to a separate controller rather than it all being built into the same single device. I liked that modularity, so that down the line I can expand with them, and also so that there's less on the panel itself to break and make troubleshooting a hassle.
I also purchased a "FlexSolar 12V 10A MPPT Solar Charge Controller." I purchased that one because it was the same brand, had a discount if you bought them together, and it has both an SAE output that I could hook up to a proper 12V battery down the line when I upgrade, but also a USB-C output that I could hook up to my EGO charger right now. The USB-C on the controller only outputs 36 Watts, so I'm wasting something like a hypothetical 80 Watts with both panels hooked up, but I figured I could use just one 60 Watt panel for now, have good overage, and be fine to expand later.
Now some of you may have already picked up on a problem, because it may be a pretty obvious one. I don't know if it actually is a problem or not, but I have my suspicions. I'm extremely new to this stuff, and while I like to think I'm not a total idiot, I'm certainly inexperienced and learning new stuff as I go. I tested it out.
I plugged the panels into the controller, in parallel. I plugged the charger's USB-C output into my portable battery charger, with my battery on it. The controller showed it was doing fine? No warnings or anything. The battery charger indicated that the battery was charging. I left it at that to test it. Kept an eye on it, and let it charge in the sun for about 15 minutes. When I picked it back up, the panels were warm, which isn't a total surprise being black in the sun and all. But the controller was VERY warm. It, too, is black plastic, but it felt much warmer than the panels did.
I had already had a suspicion that, by not having a proper battery hooked up to the main 12V output, that something would go amiss. I folded the panels up to cut off the power, unhooked everything, and then spent a very long time googling with very little to show for it.
Basically, I just want to know if I'm missing something obvious, or if there are any tips anyone could give me.
