Portable Battery & Solar power for ham radio

There aren’t too many days going by when someone doesn’t say “I need a bigger battery to operate longer”. This is almost the most ridiculous statement I’ve ever heard, and it shows many of us still don’t get it.

QRP or QRO portable ops is a constant battle between saving weight, and increasing operating time. Unless you’re on foot like I usually am, the larger battery capacity is going to win the argument. What if I said “increased battery capacity is not the only way to increase your operating time”? Well if you have daylight, there’s very little reason to increase the size of your battery. I’ll explain.

In the video below this paragraph, you see me deploying a 100w radio with the relatively small capacity battery (10ah). What you will also see, a charge controller and a solar panel. You see, we have to make a choice between the increased size and weight of a large capacity battery pack, versus the size and weight of a capable solar panel with a smaller more portable battery pack. Sometimes a larger capacity battery pack wins the race, because of the watt hours per gram/ounce of lithium or lithium iron phosphate cells. On the other hand, what if you have a finite amount of storage space during your deployment? If you quite literally don’t have enough space for a larger battery, a lightweight flexible solar panel might be a better option?

When you have limited space for larger capacity packs, one solution is deploying solar power to augment the storage capacity of your battery. I know some of you will say “just take a second battery pack”. Taking a battery pack might not be practical for one simple reason. When your batteries die, your radio becomes a boat anchor.

For this reason, especially in the emcomm and preparedness communities, the ability to replenish our battery packs, means we can use smaller capacity batteries, without loosing operating time. Sounds too good to be true. Well it almost is. There is one issue with this way of operating. If you plan on operating 24/7, the larger capacity battery pack is always a reliable option. With the solar panel, we must ration our power during hours of reduced sunlight. That means only operating at 100 Watts when the Sun is up and hitting your solar panel. When it’s not, we need reduce power until sunlight returns. It also helps to deploy a more efficient antenna system, or more efficient operating modes. See the relationship between all components and systems?

In the next playlist “Battery & Solar Powered Portable Ham Radio Outdoors”, you’ll find various examples of battery powered operating, with and without a solar panel to augment my battery. When operating without a solar panel, we go home when the battery dies. When operating augmented by solar power, we do have to adapt dynamically, making the most of the available power but, at no time do we need to stop and go home.

This last playlist is my portable off-grid battery and solar power for amateur radio communications playlist. There are lots of projects and explanations about off grid portable power.


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Julian oh8stn

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