My brother gave me two used panels, unknown specs. They are about 12" x 36", unloaded, and overcasted, I got 16V to over 20V (scale). Wasn't enough sun to get into further tests. Figuring from the size, they are consistent with my 14w and 18w panels. Was wonder if there is much of a problem just hooking them up in parallel, and using a single charge controller. Up until now, I've been trying to keep everything matched, but want to use a large battery, and need higher current. I've got a 1500 watt inverter, and hope to run a few small appliances.
Just wonder if it'll matter much using different size panels together. My brother has some of the same panels, but cracked and broken. If not to bad, should be able to salvage a few watts from some of these as well.