Building a Solar Powered Ham Radio Station

Welcome to the Off-Grid Ham Shack series. In this series we go through putting together a solar-powered off-grid ham radio station (Ham Shack). This article covers everything from solar panels, charge controllers, power distribution, and battery storage capable of powering our communications gear for fun, or in a grid-down scenario.

UPDATED 26 JANUARY 2024

Breakdown of an off-grid ham shack

Just like our portable ham radio stations, an off-grid ham shack starts with generating and storing energy. That energy can come from a solar panel, hand-crank generator, wind turbine, or some other DC source. In order to keep things simple, we will focus on a solar powered ham shack.

Battery storage
Wind turbine
Adding first solar panels (old video)

In a solar-powered ham shack we have a few common components.

  • Solar panels
  • Charge controller
  • Battery
  • Power Distribution

Let’s go through the job and purpose of each one in our off-grid system

Solar panels

Solar panels, also known as photovoltaic (PV) panels, harness sunlight and convert it into usable electricity. Each panel consists of multiple solar cells made of semiconductor materials, generally silicon. When sunlight hits these cells, particles called photons are absorbed, creating an electric field. This electric field allows electrons to flow, generating direct current (DC) electricity. The generated DC can be used to charge our batteries, or power our ham shacks.

The solar panels we use for fixed installations are much more cost-effective than the portable panels we’ve seen on the channel and blog previously. This makes our fixed off-grid installation more “budget-friendly”, compared to the lightweight, man-portable options we use in the field.

Some operators for whatever reason, can’t or don’t want to put up permanent solar panels. These operators might chose to put up less portable solar panels, while their stations are in use. This is especially useful for those using their equipment periodically, just needing to top up the battery storage after a few hours of use.

Folding suitcase solar panel, battery and charge controller.

Ultimately, deciding which type of solar panel is right for you, isn’t something someone else can do for you. For the off-grid ham shack, I chose 5x Renogy 100-watt rigid panels as the core of the solar panel system. These were chosen for being well-designed, having a great warranty, and cheap delivery costs. I decided on a larger number of smaller panels for redundancy, versus a fewer number of larger panels, with little or no redundancy at all.

Solar charge controller

Since charge controllers are not all the same, don’t be tempted to rush out and buy a cheap rebranded charge controller! A solar charge controller acts as a gatekeeper for your solar storage system. It insures our batteries are optimally charged, protected from overcharging, deep discharging, and maximizing the overall efficiency of our battery storage system. Your charge controller should do all this, while being RF quiet! This means they shouldn’t create noise in your radio equipment.

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A solar charge controller, also known as a solar regulator, is a critical component in a solar power system. Its main function is to regulate the flow of energy from the solar panels to the battery/batteries while preventing overcharging or damage to the solar storage system. Don’t let anyone tell you a charge controller is not required!

The solar charge controller is the first and last defense in protecting our battery. Here’s how:

  1. Current Regulation: When sunlight hits the solar panels, the panel will generate direct current (DC) electricity. The charge controller helps regulate (or limit) the amount of current from the panels to the batteries. It ensures that the batteries receive the appropriate charging current, preventing the battery from being overcharged, or charged at too high current.
  2. Battery Protection: Solar charge controllers monitor the battery voltage. The charge controller will alow charging when the battery voltage is within certain voltage limits. It will also prevent charging of the battery, if the battery is full. These features help protect the battery from excessive discharge, and inadvertently oversharging our battery. Both scenarios can lead to damage or reduced battery life.
  3. Preventing Overcharging: As mentioned above, overcharging can damage the batteries and reduce their lifespan. Solar charge controllers use a technique called pulse width modulation (PWM) or maximum power point tracking (MPPT) to prevent overcharging. PWM controllers (Bad!) regulate the charging voltage by pulsing the current flow to the batteries, while MPPT controllers optimize the solar panel’s output voltage to deliver maximum power and adjust the charging parameters accordingly.

My preferred charge controller is the Genasun GV10L for 4S LiFePO4 batteries. It has a proper CC/CV (constant current, constant voltage) charge profile which is required for Lithium based battery chemistries. Never use charge controllers meant for lead-acid batteries, with your lithium based battery packs. The CC/CV charge profile has no need for float, bulk, absorption… used in lead-acid batteries.

Genasun USA & Europe

Genasun in North America and Europe offer discounts to my viewers and readers.

Use coupon code “5forOH8STN” for both regions.
North America: https://sunforgellc.com/genasun/
Europe: https://genasun.eu/

Full disclosure: Although I initially started testing with a Victron 75/15 MPPT charge controller, I almost immediately swapped back over to the Genasun controllers used in the field. Although the Victron controllers offer advanced features lacking in Genasun, the Genasun controllers are RF quiet! This is an important point in radio communications. No amount of extra features is worth the added RFI noise, in a system primarily used for off-grid communications.

Battery storage

In an off-grid solar system, a battery acts as a reservoir, storing the energy produced by the solar panels for later use. This stored energy can power our electrical devices when the sun is not shining, or provide additional current when current from the solar panels is insufficient. Without a battery, the solar energy generated during the day would be wasted, since it cannot be stored without one. Therefore, a battery ensures continuous and uninterrupted solar storage, in off-grid solar systems.

One question coming in is “Can we power our radio equipment directly from the solar panels?”. In theory yes! This will work fine until a cloud passes between the solar panel and sun. If your equipment takes more current than your solar panels are producing, your station will get shut down! Try to run the station at night, it’ll get shut down! If you are running a low power station, on a clear sunny day when the sun is fully illuminating your panels, sure it will work fine, within the caveats mentioned. The thing is, the battery provides a buffer between your station and solar panels. No sun, no problem, the battery will take over.

Since this project is limited by budget, I decided to give a budget friendly Lithium Iron Phosphate (LiFePO4) battery from Power Queen a try. Unlike lead-acid batteries which actually only provide ~50% depth of discharge, LiFePO4 batteries give us a real ~100% of listed capacity. This means when you buy a 100 amp hour LiFePO4 battery, you really get 100 amp hours out of it. With a 100 amp-hour lead-acid battery, the useable capacity might be 50% of its stated capacity.

For LiFePO4 cells, the efficiency of the charge and discharge rate is also very high – above 97% or more. That is why the Peukert’s exponent is close to 1.00, meaning LiFePO4 batteries don’t suffer from Peukerts law as lead-acid batteries do. Peukert’s Law, named after the German scientist Wilhelm Peukert, is a mathematical equation that relates the capacity of a battery to its rate of discharge. It states that the actual capacity of a battery decreases as the discharge rate (load) increases. In other words, the higher the current draw from a battery, the lower its effective capacity will become.

Power Queen LiFePO4 batteries.
Use coupon code: “JULIANOH8STN” in Europe, the USA and the UK, and Canada.
Europe affiliate link:
https://www.ipowerqueen.de/discount/JULIANOH8STN?ref=732d60hj
North America affiliate link:
Canada https://ca.ipowerqueen.com/?ref=y0igztbu
https://ipowerqueen.com/?ref=0q1c0pan
United Kindom affiliate link
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Battery Expansion

There are times when we want to add additional battery storage to our off-grid ham radio station. Although this is a simple process, there are some things to watch out for when connecting batteries in parallel. Here are a few tips:

  • Never connect an old battery with a new battery.
  • Always use batteries with identical voltage and capacity.
  • Never connect batteries with a high voltage mismatch.
  • Never connect batteries of different chemetries.

Power Distribution

Power distribution is a crucial aspect in of any off-grid ham shack. Power distribution takes a single DC connection or port, dividing it into multiple DC ports. The primary objective of power distribution is ensuring that the supplied connections are appropriately distributed to multiple devices or components within the system. By dividing a single DC connection from our battery storage, into multiple DC ports, it becomes possible to power multiple devices simultaneously. In regards to the off-grid ham shack, think multiple radios, computer, lighting, desktop cradle charger, … all powered through power distribution. Keep in mind, power distribution does not divide the voltage or current in the system. It is up to you to use a battery capable of providing the necessary voltage and current for the load placed on your storage by the peripherals. If you draw too much current with your peripherals, your voltage will drop! Test and measure your constant loads on your system.

Windcamp AP-8 Power Distribution:
https://ebay.us/xDXLyQ (Affiliate link)

I chose the Windcamp AP-8, 8 Port 40A power distribution board. It has one fused DC input, and 7x fused DC outputs. I decided on the 40 amp Windcamp AP-8 because my station will never approach the 40 amps limit for any reason. Generally, with all my radios transmitting simultaneously, the maximum current load on my battery storage is ~25 amps. With one port reserved as the primary input port @40 amps, the other 7 ports are divided by maximum potential current from the equipment connected to that port (up to 40 amps).

Wind Generator

Other considerations

AC (Alternating current) or DC (Direct Current) Ham Shack?

DC electricity, short for Direct Current electricity, is a type of electrical current that flows in one direction. In a DC circuit, the flow of electric charge remains constant, maintaining a constant polarity. This means that the positive and negative poles of the circuit always preserve their respective charges. DC electricity is commonly produced by sources such as batteries, solar cells, or DC power supplies, DC electricity is widely used in various applications, including electronics, telecommunications, and automotive electrical systems.

Most ham radio equipment runs on DC electricity. In fact, most mobile ham gear will operate from a range of voltages between ~12 to 15 volts. Often, portable ham gear generally operates on voltage ranging from ~9 to 16 volts. Green radios (surplus military radios) generally operate on a range of voltages ~9 to 24 volts. In the ham shack, it is important to keep our gear DC whenever possible. The target range for most ham radio gear is ~13.8 volts. Some operators mistakenly believe a slightly lower or higher voltage will negatively impact the performance of their radio. This is usually a matter of individual perspective, as most gear is designed to operate throughout a voltage range, rather than one specific voltage. What is important is providing a reliable DC output for our ham radio gear. More on this later.

For now, try to focus on keeping your ham shack ~13.8 volt DC compatible!

12 volt, 24 volt, 48 volt, battery & solar?

There are often reasons some Operators might want to run higher voltage solar or batteries. Usually, there is other non-radio equipment like DC to AC inverters, which could benefit from the higher voltages and thus, operate more efficiently. There is also the point of increasing voltage to reduce current which allows for reduced wire size between solar panels and the battery. Keep in mind when we run higher voltages, we also need to drop that voltage back down to something our radio gear can use. This process can (but may not) introduce noise into the system.

For example, one of my solar strings had 3x 100-watt panels in series. The charge controller takes that 60-70 volts from the solar panels, dropping it down to 14.4 volts for battery charging. Although this creates an excellent charging environment (in spring & summer), it also creates and an enormous amount of RFI noise during the bucking process of reducing the voltage. That noise prevents an Operator from hearing his/her radio spectrum effectively. This is unacceptable if the primary role of the station is communications.

(18 December 2023)I have replaced the 3x 100-watt solar panels in series, with a combination of 3x 100-watt solar panels in parallel. There are two benefits to this. Firstly, the panels in parallel seem to work much better near the winter solstice (no direct sunlight) than 3x in series configuration. Second, there is little if any RFI from the bucking process of the charge controller. I understood this would mean replacing the wire between the charge controllers and solar panels with heavier gauge, but the reduction in RF noise was worth the configuration change.

This is a topic we’ll need to discuss in more detail later on.


With the basics out of the way, the following video will make a lot more sense to newcomers to this topic. After watching, if you want to go down the rabbit hole, keep on reading from the section underneath this video.


OH8STN Ham Shack

From here on down, the discussion becomes more abstract.

Overview

The Off-Grid Ham Shack’s main power supply is a 12.8 volt, 100ah Power Queen lithium Iron Phosphate battery. (EDIT: 2x 12.8 volt 100 amp hour LiFePO4 batteries in parallel since 18 DEC 2024). The LiFePO4 battery is charged each day by 740 watts of Renogy solar panels. The solar panels are divided into several strings. The solar panels feed several Genasun GV10L charge controllers.

The charge controllers are connected to the 2x 100ah LiFePO4 battery packs in parallel. Each charge controller is fed by one of the multiple strings of solar panels. The strings provide redundancy to the overall system. More on redundancy later.
By the way, the Victron 75/15 MPPT has been removed from the system. Good riddance!

Most of my solar panels are oriented vertically. This is to maximize the collection of solar energy during winter months at 65° North. During spring, summer and mid-way through autumn, there is a near abundance of sunlight at this latitude. For this reason, summertime “optimal” solar panel orientation is unnecessary in such a solar-rich environment.

At this latitude, there is about an 8 week period between the beginning of December through the end of January where solar collection is extremely difficult if not impossible. During this time, I have several options for charging.

  • My hand crank generator is connected to one of the Genasun GV8 Boost controllers. This allows me to burn some calories, while topping up the 200 amp-hours of LiFePO4 storage.
  • The station also has a wind turbine. This can be used with the same Genasun GV8 Boost controller to top up the LiFePO4 batteries. Sadly the wind doesn’t blow all the time, and a hurricane is required for truly reliable charging from the turbine.
  • In extreme cases, grid power can be used for charging. This is practically blasphemy from my perspective, but sometimes we have to do it, provided the grid in up.
  • Diesel DC generator? I’ve thought of a DIY DC diesel generator using a small Chinese diesel engine, driving a small DC motor. This is someething we’ll come back to.

Solar storage

Since 18 December 2023, the off-grid ham shack has used 2x Power Queen 100 amp-hour LiFePO4 batteries in parallel. This gives the station 200 amp-hours or 2560 watt-hours of storage for the station. In practise, this amount of storage powers the station for ~7 days at 100-watts ouput, without any sunlight.

The 2x LiFePO4 packs are connected in parallel using pure copper parallel jumpers

Ultimately, the station will receive 4x 100 amp-hour batteries 5120 watt-hours in parallel. With radio equipment, lights, power for the diesel heater, computers, … 5.12Kwh is more battery storage than the station will ever need for any scenario.

Charging & Redundancy

The station uses several strings of solar panels connected via multiple charge controllers. Each charge controller is connected to a unique solar string, wind turbine or hand-crank generator. There are also spare charge controllers for adding supplemental DC sources. We’ll discuss supplemental DC inputs a little later.

The following short video shows the energy flows from solar panels, to energy storage, to consumption. Each step in the chain has built-in redundancy.

This solar panel and charge controller configuration adds redundancy to my off-grid energy system. Each solar string can feed energy to my main solar storage, independent of the other solar strings. In fact, as long as at least one string of solar panels remains, the system will continue recharging itself from solar power (albeit slower).

This is also true for the array of parallel charge controllers. Each charge controller is responsible for a single string of solar panels. A damaged or destroyed solar panel does not affect the charge controller, as the charge controller will switch into a “fault” state to save itself. If there is a short circuit between the charge controller and battery, a fuse will blow, disconnecting the charge controller from the solar storage.

There are also secondary solar storage systems in place. For example, the EcoFlow River 2 Max is fed by the 2x Power Queen 100ah LiFePO4 batteries when voltage is above 14 volts. In a pinch, the EcoFlow River 2 Max can power the Off-Grid Ham Shack in QRP mode, for up to 3 days without recharging from solar. This provides a redundant power source for the comms gear, lighting, … if something were to go wrong with the PQ 100ah LiFePO4.


There are also several DIY LiFePO4 batteries of various sizes. These are trickle charged from a 60 watt PowerFilm Rollable panel and Genasun controller. Their only role is to be ready to go if an additional power supply is required somewhere else, for some other purpose.

Radio equipment & services

My station runs several services for the benefit of my group and community. Some of these services allow local Operators and those around the world, to connect to one another for keyboard to keyboard chat, messaging, and the occasional rag chew. These services also allow Operators to reach out to others far beyond their own station’s direct capabilities, receiving advice or experience with topics outside their primary skillset. The interaction can very well be a two-way exchange of expertise or even a lifeline.

Services running on the off-grid ham shack

  • Winlink gateways on HF & VHF
  • JS8Call station 24/7
  • Robust Packet (HF APRS)

The station uses several radios and computers for grid-down communications. All HF radios run on 12 volts DC, directly from the Power Queen LiFePO4 battery.

For laptops & dual-band HTs not running 12 volts natively, I chose gear with USB charging built-in. For laptops and tablets, USB-C PD charging. For hand-held dual-band radios, USB-C charging ports integrated. This means built-in USB-C charging on the charging docks, and/or built-in on the battery packs themselves.

So far, this is working out extremely well!

Dual-band VHF/UHF charging

As mentioned earlier, many of the charging cradles on modern handheld radios come with an AC plug built-in. This is a complete no-go for the DC powered off-grid ham shack.

What we need is either a 12 volt DC plug on the radio and/or cradle, or a USB-C plug directly on the radio, cradle, and even the battery.

With so many Operators starting out with dual-band VHF/UHF radios. D-STAR, DMR, Analog, … flexible charging is critical. One new feature found on a few of the latest generation of handheld radios is USB charging.

USB charging allows us to recharge our devices with standard power banks, solar panels, … while in the field and away from the charging cradle. USB charging also reduces the amount of gear we need to carry eg charging dock and adapter cables.

I chose the Retevis RA89 & RA79 for two of my VHF/UHF analog SHTF rigs. These radios both feature USB charging ports on the battery pack and in their docking ports.

The benefit here is simplified charging, battery management, and equipment readiness in the case of a grid-down scenario. Here I’m using the EcoFlow River 2 Max as a redundant power supply. The Retevis rigs are connected to the USB output ports of the EcoFlow River 2 Max, which keeps them topped up and ready to go.

The ecoFlow River 2 Max is fed by the 100ah Power Queen Lithium Iron Phosphate battery which power my shack. This offers an amazing level of redundancy, the station has not had previously.

Ultimately, it is much easier to have a “universal” charging port like USB-C, rather than the various voltages of DC charge cradles, or AC cradles without DC charging capability. I will no longer purchase or support any radio which has no USB-C charging capability built onto the radio or battery directly.

For the dual-band VHF/UHF radios carried in my chest pack, it is critical to have them powered up and ready to go at a moments notice. Since they live in the ham shack when not in use, charging in and out of the shack should be simple and easy.


Efficiency & current consumption

When running off-grid and/or generating our own energy, it is important to keep the current consumption as low as possible while maintaining effective communications. Doing so allows us to extend the operating time of our stations, without an unnecessarily large energy collection and storage system.

What this really means is keeping each part of the station as efficient as possible. For example

  • No lossy antenna – Always use a resonant antenna when possible!
  • Ultra-low current consumption radios – 300ma or less on RX is good.
  • Ultra-low current consumption computer or tablet
  • Ultra-low current consumption LED lighting

For the most part, my off-grid ham radio station utilizes energy-efficient portable ham radio gear. The reason is “low current consumption“. While many operators look at radios like the Icom IC-7300, Yaesu FT-991A or similar, these radios have a very high current consumption, while doing nothing more than receiving! The higher the RX current consumption, the larger and more expansive our solar collection and solar storage needs become. As a rule, our current consumption goal should not exceed ~350ma on RX. Current consumption more than 500ma on RX, can become a complete no-go for sustainable off-grid or grid-down communications. It is not impossible to sustain more tan 500ma on RX, but can become costly to do so, the further one lives from the equator. The bottom line is: The more current our station uses while idling, the more solar panels and battery storage required to keep the station running off-grid.

The average RX current consumption of QRO (high power) radios is 1-2 amps. This is not a problem in a vehicle, where the engine is also our power supply. On the flip side, energy efficient QRP rigs and potentially amplifiers to augment them come in at a much higher price than their QRO counterparts. However, QRP rigs have a much lower current consumption than ORO radios. The trade-off is we can get away with smaller, less costly solar and battery storage to power them in the shack. QRO rigs are often (initially) more cost-effective to buy, but require a larger off-grid power supply to keep those stations running grid-down. It’s the old bait and switch!

Why not just reduce TX power!?

RX current consumption isn’t the only concern. QRO radios are also less efficient on transmission. Take for example my Icom IC-705 and DIY599 PA500E amplifier. Total current consumption on RX is less than 300ma. Total current draw at 100 watts is ~12 amps. As an example, RX current consumption of my old Yaesu FT-891 on RX was ~1.2 amps. On TX the FT-891 at 100 watts consumed 20-22 amps. Do you see where we are going with this? Off-grid comms is not about buying popular gear. Rather, it is about energy efficiency! Every green radio ever produced follows a “more efficient” methodology. If this fact is overlooked, our comms gear will sit quietly in the corner because we didn’t build an energy efficient system, to power it effectively. Let that sink in.

In this video, the concept of QRP & efficient amps vs QRO was introduced.

Supplemental solar generation & storage

In total, the off-grid ham shack has ~5312 watt-hours of LiFePO4 solar storage available for any grid-down scenario, encroaching upon our community. That is 3072 watt-hours of primary online battery storage, with the rest in reserve. Moreover, the off-grid ham shack has 740 watts of primary online solar panels, AND an additional 3055 watts of supplemental, field deployable solar power on reserve. Along with reserve radio gear, additional solar storage and rapidly deployable solar panels, these are stored in EMP hardened hard cases, in case the unthinkable happens.

The portable solar panels serve a dual purpose. In addition to providing lightweight portable solar power in the field, these man-portable panels can be deployed locally for augmenting solar collection at the off-grid ham shack. It’s not the most cost-effective method, but does offer some advantages, where adaptable solar collection is needed. For a bugout scenario, there is zero chance someone will carry a 20lb solar panel (for very long) in a survival scenario. A 2 to 5lb folding solar panel is a much more reasonable option. Moreover, those same solar panels can be mounted and/or moved to where they get the best sunlight. They can also be stored securely indoors at night, when bad actors come out to play. A few portable solar panels should be part of every off-grid stations inventory.


Why no inverters?

Every time I publish a video on off-grid solar power, someone comes along a says “WIll Prouce” says bla bla bla. Will is incredible, and I watch his channel myself. The thing is, Will focuses on energy for the RV, the cabin, the van, the workshop, and even the home. Most people don’t/won’t understand the red flag here but here it comes. Those systems generally use inverters and higher voltage. They have higher voltage solar arrays, higher voltage batteries (if they have batteries at all). The problem here is most radio communications gear runs on 12-15 volts of DC power. This means we will need an inverter to convert xxx volts AC to power a DC power supply outputting 12-15 volts for our radio equipment. This method has lots of losses. Losses eat up our battery storage unnecessarily. So, the red flag is the inverter! Inverters are also notoriously noisy to radio communications gear. Because of this we MUST/SHOULD keep our off-grid comms power DC (whenever possible), in a voltage operating range of ~12-15 volts or ~9-16 volts for portable gear. This removes the need for any micro inverters at our solar panels, or inverters after our batteries powering the AC power supplies to power our communications gear. Don’t run comms gear off AC inverters!

This doesn’t mean we can’t have a hybrid system using inverters for some other purpose eg my air compressors, someone’s CPAP machine, or even to power an off-grid refrigerator or freezer. One of the reasons for the EcoFlow River 2 Max in the off-grid ham shack is its AC inverters. Normally these inverters are disabled. If for some reason and AC device needs to be powered up in an emergency, the EcoFlow River 2 Max can handle that job. Otherwise, the inverters are off, and not bothering anything. This page assumes your primary goal is powering your ham radio station off-grid! If you want to run an air-conditioner on solar power, this may not be the right place for you. Food for thought!

Heating the ham shack in winter

One overlooked aspect of a sustainable ham radio station is how it will be heated. In cold weather regions, heating in winter can make or break any off-grid station strategy, For my off-grid ham shack, the operating space, the operator, and the lithium batteries need to be kept above freezing.

The lithium iron phosphate batteries we use in our ham radio stations, often come with a temperature spec which states a charging range starting above freezing. Operators can function below freezing, but would certainly be more comfortable in a more mild climate.With that said, here is how I keep the ham shack and its lithium batteries warm in he harshest winter weather:

For the off-grid ham shack project, heat was important for the lithium batteries, as well as for the Operators in the shack! Of course, it was also important to keep frost out of the space, since frost can damage the radio and computer equipment we use regularly.

I decided to try a Chinese diesel heater from Vevor. This is a 3kw model. It came with most if not all of the components included in the kit to install it. This heater is detailed in the first part of the video below. Check out the thermal images of the heaters inlet vent below.

Recommended Gear

Power Queen LiFePO4

Power Queen provided the first 100ah LiFePO4 battery for the off-grid ham shack project. At the time of this writing, the first one has been in use for about ~5 months (August 2023). Naturally it will take years for a long term review of the battery, but so far so good. If something bad happens, you’ll get a new video from me pointing out the failure. Based on the performance so far, I may purchase several more of these packs for a total of 400 amp hours of active solar storage for the off-grid ham radio station.

In December 2023, a second Power Queen 100 amp hour LiFePO4 battery arrived. Since it is identical to the first battery, it’ll be connected in parallel, to make 200 amp hours or 2560 watt-hours of storage just for the radio gear. This puts the station at the half-way mark to it’s goal of 400 amp hours or 5120 watt-hours of primary online battery storage.

Power Queen discount codes

Use discount code JULIANOH8STN


Genasun Controllers

The Genasun GV10L controllers are the most RF quiet controllers I’ve tested so far. They have been demonstrated on the channel from the beginning. I do understand they are not the most cost-effective solution for multiple strings of solar, but they are RF quiet and robust. Despite the marketing from companies comparing themselves to Genasun, Genasun controllers remain a pillar in my portable operations and ham shack off-grid power strategy.

Genasun USA & Europe

Genasun in North America and Europe offer discounts to my viewers and readers.

Use coupon code “5forOH8STN” for both regions.
North America: https://sunforgellc.com/genasun/
Europe: https://genasun.eu/


EcoFlow River 2 Max

For Operators in United States, California PC & Peripherals has created a kit including the EcoFLow River 2 Max and PowerFilm 160-watt crystalline solar panel. For a low power station running off-grid. this package might be interesting. The EcoFlow River 2 Max has 2x 3 amp coaxial DC ports, 1x 10 amp cigarette lighter socket, 1x 100-watt USB-C PD port, and 3x more USB 3.0 ports. This is the perfect amount of ports to run a small Icom IC-705 based voice and data station off-grid, and on solar power.

EcoFlow River 2 Max PF 160-watt Crystalline kit

For other regions around the world, please check out your local EcoFlow distributor.


Windcamp Power Distribution

We’ve already discussed power disribution earlier in this post. Power distribution allows us to split a single DC output to multiple DC output ports. I chose rhe WIndcamp AP-8 40 amp power distribution board. Its been about a year since purchasing the first one. I have no regrets.

Windcamp AP-8 Power Distribution:
https://ebay.us/xDXLyQ (Affiliate link)


Winter charging tips

Charging is challenging in any Northern latitude. Moreso as we get closer to Arctic regions. At the time of this posts publishing, I can recharge the 100ah Power Queen battery to about 90% full each day, provided there is no sleet or snowfall. During November, December and January, we have just a few hours of day light. This can be enough if our solar panels remain clean, and we keep our current consumption as low as possible while maintaining effective communications. From the beginning of Decembr until the end of January, the days are so short there is little point in making the effort to charge from solar. If something comes in, I’ll take it. Still, I won’t be holding my breath.

If we are talkng about generating emergency off-grid power during the Winter Solstice, we really need to look at my hand-crank generator, or wind turbine to keep us on the air.

One other option might be a DC generator of some kind. That might be a great way to charge, but depending on the motor used, could create too much RFI to charge while operating.

For lower latitudes, larger solar arrays may be a good way to go during the winter months. We only have 2-3 hours of daylight (no direct sunlight) during winter solstice. 740-watts of solar is not enough! The wind turbine is realiable when there is wind, but when the wind will come is always a game of chance. There certainly is no way to reliably forecast the amount of wind, or when it will arrive.

Here are a few tips I use to maximize solar collection during winter season.

  • Reduce your current consumption!
  • Vertically mounted solar panels will keep you orienteed at the winter sun, which is generally low in the sky.
  • Use additional strings of solar panels to capture sunlight, throughout the day.
  • Genasun boost controllers help in low light. Here’s how:
    1. We can use them to boost voltage from a panel with putting out lower voltage (dark days).
    2. We can use them with solar panels running higher voltage in series-parallel, then buck the voltage down to the battery charge voltage.
    Either way, the charge controller will manage the voltage boost or buck to keep charging happening, when it would otherwise be off.
  • Whatever solar panels you think you need, double or triple them as you build your station.

Grid-Down Power for disasters

Grid Down power for communications is very often overlooked in the community. We tend to approach radio communications from a hobbyist perspective, meaning it is non-critical. I created this video some years ago to give Operators an idea of grid-down communications during a disaster. There has been many examples of disasters affecting grid-tied electricity. Our ability to power up our stations using our own power is something every station owner would aspire to achieve.

Off-grid power for emergency communications is the single most overlooked aspect of survival radio today. Whether you’re sporting a Baofeng UV-5R, a fancy DMR radio with 256bit AES encryption, or the latest greatest Yaesu FTDX-9000X, they all need a reliable source of energy to operate grid-down.
The following video goes through my off-grid power plan. The plan is focused on autonomous energy collection, energy storage, and energy distribution. The plan is robust, redundant, and adaptable. There are no single points of failure, and each component has a backup candidate, if any single part of the system fails.

The purpose of a completely off-grid radio station is continuity of communications — emergency communications, survival radio, and ultimately preparedness for and during a grid-down disaster. Many of us rely on services provided by communications “middle-men” (eg repeaters), thinking these services will bridge the gap when SHTF. That may be true in some cases, but we need to look at the bigger picture.

Quite often, portable stations, mobile stations or otherwise low-power stations find themselves reliant upon repeaters, Winlink gateways, and APRS Digipeaters, … Like Pavlov’s dogs, we have been trained to believe these types of “open” systems have an unlimited off-grid and redundant power supplies keeping these services up. There is no guarantee these stations will remain endlessly powered up during a grid-down scenario. Many of these critical services are operated by advanced Operators just like you or me. The cost of maintenance is already high, without adding on the expense of a completely off-grid and/or redundant power supply, capable of running that station in the worst of times. Because of this, we need to change the way we think. Rather than being dependent consumers of off-site services, we must:

  • Become more grid-independent and energy self-reliant.
  • Learn to communicate station to station, without “middle-man” stations in-between.
  • Deploy our own off-grid services Eg fill-in repeaters, Winlink Gateways, JS8Call & VARAC stations, …

Take this seriously. The singl biggest mistake new operators make is beleiving that repeater will be operational during a grid-down disaster.

Previous battery & power videos

In previous years, I have proposed having a power system specifically for our communications gear. That philosophy hasn’t changed! In fact, I believe it is even more important as the escalation of global tensions and beginning of end times arrives. These signs make formidable arguments for independent energy sources in the “post-pandemic” world. Yes, the world we live in has become much more dangerous. I long for the days when an earthquake, tornado, hurricane or nor’easter were the most likely scenarios to ruin our day. Please take off-grid power seriously!

Related Posts

Building a solar-powered Off-Grid Ham Radio Station for beginners
https://oh8stn.org/blog/2023/12/21/building-an-off-grid-solar-powered-ham-shack/

Radio friendly MPPT charge controller:
https://oh8stn.org/blog/2023/11/30/radio-friendly-mppt-charge-controller-for-off-grid-comms-genasun/

Current consumption and off-grid communications
https://oh8stn.org/blog/2023/11/20/off-grid-grid-down-comms-current-consumption/


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73
Julian oh8stn
YouTube: https://www.youtube.com/@oh8stn
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Blog: https://www.oh8stn.org

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5 Comments

  1. Great collection of articles on off-grid solar power for ham radio.
    I’ve been following your articles the past couple years and am keenly interested in emergency comms and grid-down preparedness.

    I’ve built 4 go-power boxes a few years ago for off grid/backup use. They started out with lead acid, but last year upgraded them with LiFePo4 batteries. I wanted to make each box self-contained so I’m adding Genesun charge controllers to the outside of each box – a couple 5A versions and a couple 10A versions. I’m experimenting with different portable solar panels for optional charging.

    I have a question about the Genasun GVB-8 (Boost) controllers.

    I purchased one, but am not sure what its optimal use is. I would really be interest in seeing a full review by you of your testing and best use cases for these controllers. What is your assessment of the best use case of the Genasun Boost Controllers, and how to best test them.

    Jeff – VE7EFF

  2. I will add that I think the only thing missing here is EMP hardening for the system. Dr. Bradley (Disaster Prepper on YouTube) has some amazing products for just that situation, he is an Electrical Engineer for NASA, he runs one of their programs. He has details Ham Radio protection instructions and products here:

    https://disasterpreparer.com/product/hamsurge/

    He also has great overall home grid protection details and products found here:

    https://disasterpreparer.com/product-category/emp-home-protection/

    Like the Siemens FS Pro 140 and High-Saturation Ferrites.

  3. NJ6F / Rich
    Great article. One thing I thought I would offer is that if you get 3 or 4 max in parallel the battery does not have to cycle deeper as much meaning the lifetime of the batteries are extended. I use the 100ah Li Time batteries which might be from same German manufacturer.

  4. NJ6F / Rich
    Another thing I forgot to mention is in your northern climates would not a series of parallel (amorphous) panels be more efficient with less pointing at the sun source out of a fixed station location because you need more of them but on cloudy or rainy days they still put out better within reason and probably do not drop off output wise as much. I have mine on the roof at a few south degree down slope but advantage is no aiming, set them flat and no need to play tag with the sun 🙂

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