Okay, I raised the topic in the other thread, my subconscious mind was probably anxious to get the info out there. So here is what I have so far. This is a sample of the backpackable solar panels available on Amazon.com, there are others I don’t have so didn’t test. Since I didn’t test every panel available (and there are a lot of them) I’ve decided to simply remove the brand names from some of the panels because they’re pretty much generic panels and there are many very similar.

It’s one thing to say a solar panel can charge a phone (all the panels tested can charge a phone which only need <5 watts); it’s another to quantify power output in raw volts, amperes and watts (ie., power) terms.  So I decided to test that.

Watts in a name? The other thing I was curious about was the wattage number in every panel’s model name. What does that number represent? As far as I can determine, it’s the max theoretical wattage of the solar cells, not to be confused with the entire system’s output.

Without further ado:


A couple comments:
I didn’t test any of the panels for durability/ruggedness.

One of my original panels functioned much worse than the others (percentage output) and that company sent me a new one, no charge at all and it was immediately apparent that it was a newer model. The solar cell configuration was different and the power out was 2.5x the original.

In general the panels with Sunpower cells did better, but since I didn’t test them all, that may be an incorrect perception.

The Goal Zero Nomad I tested is a few years old and it seems really well built. I only tested the 5V USB port, I have no use for its 15V(?) port and no way to test it.

I liked both of the Renogy units. The Renogy 21W had the highest raw output and one of the highest by percentage. The Renogy E.Flex5 seems to be a very solid product. It’s small enough that it doesn’t need to fold so no moving parts, it’s rigid and that probably contributed to its efficiency.