Renogy Firefly Review Part Two – The Guts

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Curious to See What’s Inside?

Prior to becoming a full-time RVer I spent over 25 years as an electronics repair technician. Because of this background I just had to see what is inside the Renogy Firefly.

Warning! I took the Firefly apart as part of my thorough product review and only because I’m very experienced with electronics disassembly and repair.

I strongly advise against doing this yourself. First, you will void the warranty and second it can be very dangerous due to electrical shock hazards.

Renogy Firefly review

How the Firefly is Put Together

The Firefly is held together by plenty of Allen headed machine screws. I was impressed that they used brass threaded inserts to drive them into rather than cheaper plastic threaded holes.

Disassembly was very straight forward, after removing the screws around the cases solar panel and a few on the lid hinge the two solar panels could be removed as separate pieces. They even have their own plugs.

Renogy Firefly disassembly

Weather Proofing Design

Once apart, the first thing that stood out to me was the white rubber O-ring running the circumference of the case. This will go a long way to keeping dust and water out of the internal areas. Also the battery and main circuit boards have their own separate internal covers.

Renogy Firefly Main Guts

Nice Wiring and Layout

I really like the way things are laid out and wired together inside the Firefly. Most of the wire connections are using either Molex connectors or screw terminals. As a repair tech, this design makes servicing so much easier. It is more expensive than just soldering everything in place and in my opinion a sure sign of a higher quality product.

Also, I noted that many of the wire connectors were treated with an extra coating of white goop to keep them from coming loose. It’s a nice extra touch and good to do for a portable product.

Inside the Renogy Firefly

High Quality LED Lamp

Having the unit apart I could get a good look at built-in LED lamp. It looks to be a pretty powerful one judging by the size and glass cooling fins. Many commenters on my earlier YouTube video caught on to the fact that this light has an SOS mode. It flashes it in Morse code, too cool!

Firefly built in LED lamp

Lots of Extra Space

There seems to be quite a bit of extra space inside the unit. After my initial look at the Renogy Firefly several people noted it would be nice to have built-in storage for all the included hookup wires and adapters. I agree and it certainly looks doable to me. The only drawback I can see is possibly an overheating issue. The electronics does have a fan attached internally so maybe the extra room is required for air flow.

Inverter Output Waveform Check

Sine wave output
Sine Wave output

Another question asked by folks was whether the built-in inverter was a pure or true sine wave variety versus a modified type. I happened to have my oscilloscope handy so fired it up and checked the AC output. It sure looks like it to me. I got a very clean looking sine wave displayed.

This makes the inverter higher quality and safe for power sensitive electronics. I would have no qualms plugging in an expensive laptop or tablet to the Firefly.

Video Detailing What’s Inside the Renogy Firefly


Well as an electronics tech I can say the Firefly is a quality built unit. Good circuit design, smart assembly, and high-quality components. In many areas, Renogy has gone the extra mile, even where the average customer will never see.

Next I will try some performance type tests. Things like charge time from dead to full using the AC power input and the built-in solar panels. Also, I’ll test out what kind of things will run off the Firefly’s inverter and how long they run with a full charge. Stuff like that. Stay tuned…

If you missed it check out Part One of my Renogy Firefly review

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