Off grid and SOTA, solar power

I started my SOTA this summer and I found it very nice to combine both hiking and radio activity. Here in Sweden there are many unvisited peaks in North. Next year, summer, I would like to visit a couple of those. My radio equipment is optimized in terms of weight. But has anyone set up a solar-re-chargable station? My LiPo battery stores 1800mA and it gives several hours of operation with my MTR3B or 5B. But with 7-10 days off grid I need to get some extra fuel into my battery.
Have anyone suggestion on light-weight solar panel and charger/ control unit that works? I would like to have some suggestions or experiances from such operation.

Regards, Jaan

Julian OH8STN is the off-grid guru:

My DC/DC boost converter

should also work from the 5V output of most USB power-banks, which in turn can be conveniently charged from many modest solar panels.

I got one from Anker but don’t have the model number at hand.

73 de Martin, DK3IT

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If you want to have a solar panel with 5v USB, I have done very good experiences with Xtrom AP150. (There is also a stronger variation for example the AP175)
You need a powerbank that has USB input for the solar panel and 12v output for your radio.

vy 73 de Matt HB9FVF

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Hi Grovers!

Check out Light Saver Max! 2x 5v 2a USBs and 1 x 12v 5A output. Built in 18000mah (5v) lithium, and 25w rolling solar panel. About the the side of a Glad wrap / cling film box. Will run my 817 all day without an issue - the battery delivers a RF SILENT 12.2v. For QRP ops including my new QRP Digital modes - I simply wouldn’t look any where else.

Interesting for QRO I also have the 12v balance changer for the standard hobbyking lifepo4 that I can use one battery, hook the other up to the lightsaver max to charge and then hot swap back and forward.



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That’s good to know! I’m planning to put one of these into a QCX project and now I may have to build in a way to run it from an external USB power-bank.

Lightweight panels: Foldable panels from Powerfilm Solar. Expensive but very good. There might be cheaper alternatives out there nowadays.

Charge controller: You can buy a cheap one that lets you program all the parameters depending on the type of battery you are using. If you want an example, here is how I programmed one for a LiFePo4 battery:

Using this set-up during a SOTA activation, I found some noise on the 40m band. I am planning to test it out with a more expensive and supposedly better charge controller that I bought from Bioenno (once I find it in my mess at home).

Some cables may be too long and too heavy as well and shortening them + adding some anderson power pole connectors may lighten your load and and make your activations more enjoyable.

Good luck!

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I suggest a simple DC-DC step down… you can set it to 5v out… arount 1,5 $