PV | Q R P e r

Many thanks to Anas Patel who writes:

Hello Thomas,

Your post a few days a go regarding quality LiFePO4 batteries in the UK got me thinking about solar charging my batteries during the summer.

I hope your readers in the UK can give me some pointers I’m looking to assemble a very small portable solar set-up something I can easily move between multiple locations that isn’t too heavy to travel with.

I’ve had a look around on a few forums, eBay and Amazon but haven’t got a clue what I need. Fast charge speed isn’t a critical factor for me as long as I can get some charge into my batteries on a sunny day.

I know I need a foldable panel, solar controller and maybe cables to hook up to the battery but with a million options out there I don’t know where to start but I think panels between 60/120W output would give me enough power.

I would be most grateful if your readers particularly in the UK could give me some pointers.

My 12V 12Ah battery uses F2 spade terminals and the 30Ah uses M5 ring terminals but I have no issues using crocodile clips to make the connection.

Thank you.

Anas Patel

Thank you for your question, Anas.

While I know what is needed in theory (a PV panel, a good charge controller, cables, and a battery), I don’t know the charge controller market that well. As with batteries, I assume product availability may vary greatly by region.

I typically pair my IC-705 with a 3 to 6 aH Bioenno LiFEPo battery pack.

I do know this: it’s important that your charge controller is rated for the battery chemistry you have/adopt. In other words, if you’re using LiFePo4 batteries, make sure the charge controller is rated for LiFePo4.

Another thing to keep in mind is that many solar panels are terminated with industry-specific connectors like the MC4. Sometimes you can integrate those connectors into your system, other times you may prefer terminating them with other connectors.

My hope is that readers might chime in with the components they successfully use in their portable charing systems. Please comment!

This is timely because I’m actually plotting a portable PV system for my field kit and will be taking notes. I can’t decide if I should simply piece together a system around existing components I have (I would need to connect a couple small folding panels in parallel a get a LiFePo4 controller) or if I should simply go for an all-in-one system like the PowerFilm Solar Lightsaver Max.

This year, during our family’s summer holiday, I’m enjoying the hospitality of Prince Edward Island, Canada (hence, the lack of recent posts on QRPer). This is our family’s second visit to the maritime island, and each time we’ve been fortunate to stay at the same off-the-grid cabin on the eastern coast, less than twenty meters from the water.

Of course, staying in an off-grid cabin comes with its radio challenges—namely, supplying power—but also comes with one supreme advantage: no noise from the typical electrical devices that plague most of our homes. What’s more, this cabin sits on 60 acres, so not even a neighbor’s home appliances disturb my RX ears.

On our previous visit, I brought my (then) Yaesu FT-817, a 9aH gel cell, Micro M+ charge controller, 10W Solarex PV panel, some 300 ohm window line, loads of 22 AWG wire and an LDG ATU. Unfortunately, I found I had very little time for radio, and propagation was dismal. Indeed, it was during that trip that I discovered my FT-817’s finals had blown, so part of the time I was transmitting less than QRPpppp levels.

This year, since I knew the site well, I came better prepared.

My full 2012 setup consists of the following:

An Elecraft K2/10
An Elecraft KX1 (4 band w/built-in ATU)
Elecraft T1 ATU
LDG 4:1 Balun
One 35 aH gel cell
Two 9.5 aH gel cells
Two PowerFilm Solar foldable 5 W PV panels
My radio toolbox with various connectors, crimpers, cutters, wires, caps, multi-tester, etc.
Enough wire and 300 ohm antenna line to make a couple of wire antennas

So…how’s it all working out? Brilliantly!

In the past few years I’ve done a lot of QRP CW—mainly rag-chews with some buddies on the lower bands. I’ve done less QRP SSB phone. When I first arrived at the cabin and began the process of unpacking, I couldn’t find the jumper cable to attach to my Vibroplex single-lever paddle (the paddle being a Dayton 2012 find, by the way). So, I plugged in a microphone and tuned to the phone portion of the 17 meter band.

Talk about radio fun!

I’ve once again re-discovered the joy of operating QRP SSB. It’s challenging to make those DX contacts and to transmit a long call sign (“VY2 portable K4SWL”) across the ether, but occasionally the propagation gods smile upon you, and you’re able to participate in a good rag-chew or quick DX with a 57 to 59 signal report.

Being 20 meters from the salt water is a bonus I don’t usually enjoy in my US hermitage. Due to its excellent propagation characteristics, despite my lower power set-up, I have easily worked stations from Russia to North Africa, from the Caribbean to Japan. I am thoroughly reveling in it, and the process has re-connected me with my ham radio roots.

As Gunter, VA3GA, told me in a recent Canadian rag-chew, “ham radio holidays give you a chance to explore areas of the hobby you don’t normally think to enjoy.”

So true, Gunter. That’s what I love about ham radio in general– the hobby is so broad, you constantly discover and re-discover favorite elements about it.