Those of you that read the final article for my spring-break Florida POTA trip know that I recently reconciled with someone dear to me. This man, Glenn W4YES, has moved to Savannah, Georgia and we are in a relationship. He is a CW op and the person behind CW Innovations’ Comprehensive ICR course. He knows how much I love POTA and joined me Friday, May 3rd for an activation.
I could have resumed my quest for 60 new-to-me parks. However, I figured we had enough “new” stuff going on with a new activator and a different set up for Glenn. POTA tends to throw the unexpected at you already and the more variables you add, the more opportunities there are for mistakes (er, learning opportunities) and/or hilarity to ensue. So I chose to return to Evans County Fishing Lake (US-7464), a site already known to me, for our dual activation.
photo: Glenn W4YES
What a gorgeous day! Sunny skies and 71 degrees! The drive is a short (about 50 minutes) and easy one to this park.
Given Glenn would use QRO equipment and didn’t have a chair or knee board like myself, I chose one of the few spots with a picnic table. The site looks out on Bidd Sands lake. We could have shared my QRP set-up but decided to activate at the same time which necessitated two sets of equipment.
road in the park. photo: Glenn W4YESboaters on the lake
I chose familiarity over reinventing the wheel when it came to picking equipment for Glenn – I grabbed my Yaesu FC-50 tuner and Yaesu FT-891 rig from my ham shack and the Pacific Antenna 2040 trap dipole antenna and SOTABeams travel mast from my equipment stash. This was the set-up I used for POTA before I went QRP with the KX2 and Tufteln EFRW last May. It wasn’t long before a station was set up on the picnic table for Glenn. However, the antenna was another matter.
Glenn’s set up
When I grabbed coax for the antenna, I forgot the connector is a BNC connector which is why I have a coil of RG-174 in my stash. Instead of grabbing that RG-174, I grabbed my 50’ coil of RG-8x. (Doh!) That coax is extremely heavy for the SOTABeams travel mast and, after adding an adapter for the BNC to SO-239 connector, the antenna was hanging over precipitously. It just goes to show how well-made and durable the SOTABeams travel mast is. I was mortified as I like the best possible arrangement for my antennas but Glenn wasn’t. He knew what we had was good enough for contacts (see his QSO map down below) and his thinking turned out to be correct.
20-40 Pacific Antenna
While Glenn finished getting everything in order for his activation, I began setting up for mine. I know this park allows antennas in the trees so it wasn’t long before the trusty Tufteln EFRW was installed. Daisy and I chose a shady location near the antenna, got comfortable, and began my activation.
attaching throw weight to arbor line. photo: Glenn W4YESgranny swing to snag the branch I want. photo: Glenn W4YESgetting down to business! photo: Glenn W4YES
As Glenn was running QRO (the power I usually run on my Yaesu FT-891 is 75 watts) on 20 meters, I began working other bands. I initially wondered if I would have any difficulty running a QRP station so close to a QRO set-up, but I didn’t. Continue reading The POTA Babe Gets a Partner!→
Over the past few years, I’ve received numerous requests to check out the Yaesu FT-891 HF transceiver. Almost all of my ham friends have one and they are widely considered one of the best 100 watt HF radios for park activators. Indeed, I bet it is *the* most popular 100W radio among POTA activators.
I’ve been tempted to ask Yaesu for a loaner model and I even came within one button click of ordering a new FT-891 from DX Engineering during a Black Friday sale in 2020.
I’ve resisted the FT-891 temptation, though, because I tend to use smaller, more portable QRP radios in heavier POTA rotation. I knew if I purchased an FT-891, it just wouldn’t get a lot of field use. It also demands a beefier field battery due to its current requirements and, frankly, it’s so rare I run more than 5 watts (and 5 watts is the lowest power setting on the ‘891) I would simply have a lot of radio for my needs.
A few weeks ago, however, a friend reached out because he wanted to sell his FT-891 and 30Ah Bioenno battery and downsize to a smaller field portable radio like the Xiegu X5105. Long story short, we worked out a trade/purchase which included the ‘891 and his battery. I had been thinking about a large capacity battery to use as a backup in the shack, so this worked out well for both parties.
Zebulon B. Vance Birthplace (K-6856)
On Tuesday, March 14, 2023, I once again had an hour to fit in an activation at the Vance Birthplace before picking up my daughters at school. I’ve really enjoyed the opportunity to play radio at Vance so much during this particular school term; next term, it’s unlikely I’ll have this opening, so I’ll enjoy it while I can!
I deployed the Chelegance MC-750 vertical again. I’ll admit that it’s so convenient keeping an antenna in the car trunk/boot that can be made resonant so easily from 40 meters and higher.
I was going to show the antenna deployment again in my activation video, but received a call and decided to deploy the antenna while finishing up the phone call. It only takes a couple of minutes to set up.
Next, I connected my 15Ah Bioenno battery to the FT-891. Even though I was only using five watts, the ‘891 needs more capacity than the 3Ah packs I normally carry with my QRP rigs.
I received an email from a reader’s spouse asking about gift ideas for the holidays and beyond; ideas that could not only be used this month, but also tucked away for the future. They weren’t looking for the obvious things like a transceiver–they were looking for accessories that might enhance their significant others’ field radio fun.
Being the enabler I am, I was happy to oblige and, in fact, decided to turn my reply into a post (since it quickly turned into a very long email) with their permission. For obvious reasons, I’m keeping their ID secret! 🙂
Here’s a rather random sampling of things that came to mind. I tried to limit this to items that retail for less than $100 US. Note that some of these product links are affiliate links:
A quality LiFePO4 battery
Being a QRPer, I don’t need a large battery to enjoy hours of radio fun per charge. My favorite battery chemistry is LiFePO4 due to its weight, safety, shelf life, and recharge cycles (which is in the thousands as opposed to hundreds).
For me, a 3Ah battery is more than enough capacity to keep my QRP radios on the air for 3-5 activations per charge (depending on length of activation, etc.).
I’m a big fan of Bioenno batteries. Their customer support is excellent. You can purchase their 3Ah 12V battery for $64.99 US including the charger. If you already have a charger, the battery alone is $49.99. Click here to check it out.
If your significant other likes to push 100 watts, consider a larger capacity battery. I also have a 15Ah Bioenno battery for this purpose, though it exceeds the $100 gift price threshold). Click here to check it out.
A very affordable Li-Ion rechargeable battery
One of the most affordable rechargeable battery packs for the QRPer in your life is the TalentCell Rechargeable 12V 3000mAh Battery Pack. This pack typically costs around $30 US and is sometimes even less expensive.
This little pack is great because it will not only output 5V to recharge USB devices, but it also outputs 12 volts which is brilliant for QRP radios like the Elecraft KX series, TX-500, FT-817/818, Mountain Toppers, Penntek TR-35, Venus SW-3B, and many others. I actually now pair this with my QCX-Mini. The battery comes with the charger and standard barrel connectors on the included DC cord which fits Elecraft and Penntek field radios among others.
This is a small battery, so can only be paired with efficient QRP radios.
While I don’t consider this a high-quality solution like a Bioenno battery, it is insanely useful and affordable. Click here to check it out.
Morse Code Keys!
I could easily write a series of articles about Morse Code keys. That’s not what you’re looking for, though, right? You want some quick suggestions. Here is a sampling of some of my sub $100 favorites listed in alphabetical order.
CW Morse “Pocket Paddle” ($44.95): This must be one of the most popular set of portable paddles on the market. They’re affordable and very well-built! There are several versions and colors available.
N6ARA TinyPaddles ($24.95): I believe every CW field operator should carry a set of N6ARA’s TinyPaddles. They were originally designed to be backup paddles, but I know many ops that use them as their primary set in the field!
If your budget is flexible, you might also consider these paddles which are still less than $200:
CW Morse CNC Machined Aluminum Paddle ($129.95): These are very high quality, durable CNC machined aluminum paddles. Last week, I dropped them on a concrete floor from about 5 feet and they survived without even a scratch.
BaMaKeY TP-III Ultra-Compact Paddles (155 EUR): This is a high-quality, lightweight portable key that I also recently purchased. I’ve a number of friends that love their TP-III paddles!
You might recall from my previous field report that I took the family on a camping trip at New River State Park in April 2022. During that trip, I made an activation of New River each day and also fit in a very fun SOTA activation (click here to read an overview).
Note that anytime you’re performing an activation over multiple days at any one park, you can only have one activation per UTC day.
I’m often asked if I ever charge my LiFePo4 batteries in the field via solar energy.
Truth is, I’m a big fan of solar, but I’m rarely in the field long enough to need to recharge my batteries via solar when performing SOTA and POTA field activations. It’s easier to charge them at home in advance (often via the solar system at our QTH).
In fact, one of my 3 Ah LiFePo4 Bioenno batteries can easily take me though 3-5 activations or possibly more, depending on the length of the activation and the rig I’m using.
Photo by K4TLI
For longer forays into the field, however, I love going solar.
Indeed, every few years, my family will stay in an off-grid cabin on Prince Edward Island (Canada) for up to 6 weeks at a time. Solar is the only practical way to stay on the air that length of time.
Of course, I also like having a solar option, when doing proper primitive/off-grid tent camping.
In the past, I’ve used a very simple portable solar charging system based on a variety of rigid and folding panels, a Micro M+ charge controller, and sealed lead acid batteries. The batteries are of course heavy, but they work brilliantly for fixed operations.
These days, I’m fully invested in LiFePo4 batteries and my Micro M+ charge controller is not really designed to pair with the BMS (battery management system) in my Bioenno packs.
I contacted Buddipole with a few questions about the unit and to find out when they would be in stock again (at the time, they were on back-order and indeed they are at time posting this report).
There’s no cure for my pack obsession. I’m constantly in a state of assembling and testing the most efficient kits I can conjure up.
Since I rotate a fair amount of radios in my activations, the majority of my kits are modular; meaning, components like antennas, ATU’s, batteries, log/pen, and cables are packed in their own small pouches/pack. Before embarking on an activation, I simply assemble the components in a backpack along with the radio/s I might use that day. Over the years, I’ve developed a certain workflow with this process that ensures I don’t forget components or pack the wrong ones.
But by far, my favorite type of kit are those that are fully self-contained–proper grab-and-go kits that have everything I need inside to, for example, activate a summit.
Many thanks to Vitor Morais who asked the following question in the comments section of my YouTube video:
Hi,
Greetings from UK. I recently learned that POTA [is now in the] UK so I am really looking forward to it.
I also recently put an order for [the Discovery TX-500] so I am really excited as well.
I would like to create a very compact setup pouch for field use to pair with this radio; one that I could take to summits or parks and also travel abroad.
What battery and antenna would recommend?
Would you recommend an ATU?
Or would you compromise to fewer bands or pack a secondary antenna?
I love to know your opinion. Thanks
Great questions, Vitor! In truth, these sorts of questions are easy to ask but quite complicated to answer due of the insane number of options and possibilities available. It’s impossible to cover them all so I’ll try to give you some suggestions based on what I tend to use in the field. Continue reading “What battery, antenna, and ATU should I pair with the Discovery TX-500?”→
So I just finished putting together a dedicated, compact field kit for the QCX-Mini. I’m planning to do a SOTA activation tomorrow, if the stars align. Hopefully, they’ll align!
One of the newest products in this kit is my high viz 2mm x 50M Marlow throw line. I learned about this throw line from Mike (W4MAF)–thank you, Mike! It is much less bulky than standard poly throw line and fits in my Tom Bihn small travel tray. We’ll see how well it works tomorrow. First impressions from having used it at the QTH once was very positive.
Again, with any luck I’ll have this kit in the field tomorrow on a summit. If you’ve nothing better to do, look for me on the SOTA Watch spots page!
As I mentioned in a previous post, I do love rotating out radios I take to the field. Shuffling radios not only helps me remember a radio’s features and menu system, but it helps me understand any advantages one radio might have over another.
One radio I use at the QTH a lot is the Mission RGO One. I reviewed this radio for The Spectrum Monitor magazine, and later posted the review on The SWLing Post. It has been a few months since I posted a field report and video using this rig yet it’s one readers ask about all the time because this is a small production run radio.
Before heading out to Lake Norman State Park on August 9, 2021, I grabbed the Mission RGO One, the Chameleon CHA LEFS sloper, and my 15Ah Bioenno LiFePo4 battery. I knew this combo would serve me well as propagation that day was in the dumps!
Lake Norman State Park (K-2740)
Lake Norman is such an effortless park to activate. They’ve a huge picnic area, large trees (for both antenna support and shade!), and are typically not incredibly busy during the week. I love Lake Norman because they also have a very nice Lake Shore Trail I enjoy hiking post-activation.
That Monday morning, as I drove to the park, it was approaching lunch time and I did worry that some of my favorite picnic spots might be taken, but when I arrived, I was happy to see I pretty much had the place to myself!
Setting up the CHA LEFS sloper antenna takes a couple minutes longer than a standard end fed antenna only because the feed point is elevated and the radiator slopes down from the feed point. Since I typically do activations on my own (with no extra hands to help), I find that a little extra antenna prep equates to a quicker overall deployment.
My procedure for deploying the CHA LEFS
The CHA LEFS sloper
First thing I do is identify a good tree limb at least 45′ or so high and also identify an unobstructed path for the sloping radiator to travel.
Prior to hoisting the antenna, I stretch out the radiator and attach it to a tree or support (using the supplied paracord) in the direction I want the slope to follow.
I then use my arborist throw line to snag the desired tree limb and I connect the end of the throw line directly to the CHA LEFS’ feed point. Chameleon provides Paracord for hoisting the antenna, but the great thing about the arborist throw line is that it’s more than strong enough to handle this job. It saves the extra step of pulling paracord through the tree.
Next, I attach a 50′ length of coax (PL-259s on both ends) and stretch the coax out in the opposite direction of the CHA LEFS radiator. Doing this keeps the antenna from spinning and tangling the radiator and coax as it’s hoisted into the tree.
Finally, I simply pull the throw line and raise the antenna feedpoint to the desired height. Again, I like a height of at least 40-45′, but lower will still work. As I raise the antenna, I do put a little tension on the coax feedline just to keep it from swinging around the throw line or radiator.
Of course, if you have two people, one person can simply stretch the coax as you’re raising the antenna feedpoint which will also keep it from tangling.
That’s all!
In truth, the amount of extra time to deploy the CHA LEFS as opposed to, say, an end-fed half wave is maybe three minutes.
I picked the Mission RGO One because it has an amazingly quiet receiver and handles QRN like a champ. Plus, being a tabletop radio, it also sports a proper speaker, large controls, and up to 50 watts of output power if needed.
Although I’m a QRPer, on days with horrible propagation, I have been known to increase the power beyond 5 watts if operating SSB especially. This year, I set out to validate all of my park and summit activations with 5 watts or less, so at least my first ten contacts at a park will be QRP.
I thought I’d start by calling CQ on the 40 meter band in CW. Within 15 minutes, I snagged the ten contacts needed for a valid POTA activation. I was very pleased with this.
Since I had mobile phone service, I checked the POTA spots and worked AA3K (Park To Park) then moved to the phone portion of the 40 meter band.
During the exchange with AA3K, I did pump the power up to a cloud-scorching 20 watts! A proper rarity for me.
I then worked an additional five contacts in about 8 minutes in SSB. Very satisfying!
QSO Map
Here’s my QSO map of the entire activation. The red polylines represent SSB contact, the green are CW:
I was very pleased with the results especially after reading reports from other activators that same day who really struggled to get their ten.
Video
Of course, I made one of my real-time, real-life, no-edit videos of the entire activation. If you’ve never seen one of my videos before and have a strong dislike of professional, well-polished YouTube channels, you’re in for a treat! 🙂
Post-activation–and despite the heat and humidity–I hiked the length of the Lake Shore Trail; roughly six miles. I highly recommend this trail if you can fit it into your schedule.
Thank you!
As always, thank you for reading this report and thank you to those who are supporting the site and channel through Patreon and the Coffee Fund. While certainly not a requirement–my content is always free–I really appreciate the support.
Here’s wishing everyone a little radio fun this week!
In 2020, I easily spent a total of 100 hours outdoors with my radios activating a total of 82 sites for the Parks On The Air (POTA) program alone. This doesn’t include hours and hours of SWLing (shortwave radio listening). It’s been great.
Taking radios into the field is so much easier to do today than it was in, say, 1985 or earlier, because we have so many more options for powering our gear in the field. Not only have radios become more efficient in operating off of battery power, but we now have so many affordable and lightweight rechargeable battery choices on the market.
In the following article, let’s take a look at some portable battery power options for your radio gear. By “portable,” I’m talking power options for those of us who load a backpack or carry case and head to the field.
To keep the scope of this article in check, I’m also going to focus only on rechargeable battery options. And rather than get bogged down in the nuances of battery chemistries, we’ll focus on the end result––the pros and cons of each battery type, and how practical they might be for your field application.
In addition, I’ll also limit discussion to batteries that can be purchased of-the-shelf rather than addressing homebrew options. While I love building things, I’m very cautious when dealing with battery charging because if not done correctly, the results can be dangerous. I prefer obtaining products from trusted suppliers who thoroughly engineer and test their equipment.
Let’s take a look at several types of batteries, and speak to their advantages…as well as disadvantages. Then––as we summarize our findings––let’s discuss how to choose the right option for your needs.
Consumer-grade rechargeable batteries
Let’s begin by talking about the lowest-hanging fruit in terms of portable power: everyday rechargeables in the form of 9V, AA, AAA, C, and D cells.
While, admittedly, these batteries are not typically an option because of their limited capacity and energy density, they can still be a very practical power source for portable receivers and even a few QRP transceivers.
Rechargeable battery chemistries have improved with time, thus I no longer purchase nickel-cadmium (Ni-Cd or NiCad) or legacy nickel metal hydride (NiMH or Ni–MH) batteries.
These days I almost exclusively purchase low-self-discharge nickel metal hydride (LSD NiMH) batteries, specifically, Panasonic Eneloop batteries (Amazon affiliate link). Although they’re a pricey option compared with generic NiMH batteries, and might even be overkill for certain applications, I do love the shelf life of Eneloops.
Of course, the benefit here is Eneloops have that low self-discharge. They will maintain charge better at rest (i.e., when not in use) than legacy NiMH or NiCad batteries. From my real-word usage, I’m convinced that Eneloops also demonstrate better longevity over numerous charge/discharge cycles than many others.
All of my portable shortwave receivers that accept AA or AAA batteries are powered by Eneloops exclusively.
And although I’ve never done this myself, it is also possible to power highly-efficient QRP transceivers with Eneloop batteries, so long as you use a multiple battery holder to increase voltage and capacity to match both your rig and your desired amount of operating time.
WD8RIF’s AA battery holder
Keep in mind, though, that most transceivers will require a block of at least ten AA batteries to reach a voltage around 12 VDC. As you might imagine, it can be cumbersome after using your radio in the field to remove all ten of these batteries and charge them in a charger that can only hold, say, four batteries at a time. I personally prefer other options, but this one is certainly a fairly affordable, safe, and accessible option.
Note that in recent years, Panasonic started offering Eneloop Pros: while pricier than standard Eneloop batteries, they offer slightly higher capacity at the expense of overall longevity (roughly 500 versus 2100 total charge/discharge cycles). Since the voltage is the same, I’ve never felt the need to use higher-capacity Eneloop Pros.
Rechargeable Panasonic Eneloop AA batteries (non-Pro version):
Price: $2.25 – $4 US per battery, depending on the number in the package
Weight: 4 grams/.4 ounces per cell
Voltage: 1.2 V each
Longevity: Excellent, up to 2100 charge/discharge cycles
Ease of recharging: Simple via Eneloop OEM chargers
Solar- charging option: Eneloop originally marketed solar chargers, but doesn’t seem to do so presently
Sealed Lead Acid (SLA) Batteries
When I first became a licensed ham radio operator in the late 1990s, sealed lead acid batteries were the primary battery power source used for field radio operation.
At the time, these batteries were one of the best options for portable radio use because they could be purchased in a variety of sizes (based on amp hour capacity), and unlike flooded lead acid batteries, they required no maintenance––and being sealed, did not outgas.
While I’ve owned everything from 3 Ah to 15 Ah SLA batteries, I found the once-ubiquitous 7-8 Ah size to be the “sweet spot” in terms of portability and capacity.
SLA batteries are still among the most accessible high-capacity batteries on the planet. No matter where you travel, it’s likely you’ll be able to hunt them down in any hardware or electronics store. Our small local hardware store has a wide selection of these at their battery kiosk.
What are some of the pros of these batteries? In terms of “bang for buck,” the SLA is still hard to beat. You can purchase a quality 7.2 Ah 12-volt SLA battery for about $18-20 US (affiliate link). This would be more than enough battery to power a typical QRP transceiver for many hours on end. Chargers are also inexpensive––you can purchase a dedicated charger for about $10-15 US. Not bad.
In addition, 12-volt batteries are nearly ideal for amateur radio use since most transceivers are designed to operate with 12-13.8 volts DC +/- a modest margin.
There are some negatives compared with more modern battery chemistries, however. For one, SLA batteries are much heavier than the batteries we’ll discuss in the following sections. After all, they’re (still) made of lead! In addition, the battery’s longevity will be negatively impacted if you discharge it too deeply.
With that said, if you take care of an SLA battery, it can give you five or more years of service life in the field, yielding an excellent value for the modest investment. If you have an application that requires relatively little capacity from the battery, you might get a very long service life, indeed. In 2011, I built a remote antenna tuner box around an LDG Z11 Pro ATU and a discarded 7Ah 12V SLA battery. At the time, this battery could no longer hold voltage long enough to be reliable in the field, but I knew the Z11 Pro requires very little in the way of power, so I thought I’d try it as a power source anyway. Since the remote ATU box isn’t near an outlet, I charge the SLA battery with a 5-watt solar panel I purchased used at a hamfest with a Micro M+ charge controller. A decade has now passed, and that SLA battery continues to power the Z11 Pro even through seasonal temperature variances of -10F/-23C to 90F/32C. Not bad! Again, keep in mind this application works because the Z11 Pro is so flexible in terms of power requirements––it’ll operate on 6-16 volts DC at 300 mA with a 20 uA standby current.
Clearly, SLA batteries are affordable candidates for back-up power in the shack during occasional power outages.
Price: Most affordable option per Ah of the batteries listed here
Weight: By far, the heaviest of all the battery options in this article
Voltage: Various, but 12VDC is very common
Longevity: Very good if properly maintained
Ease of recharging: Easy, via simple charge controllers
Solar charging option: Multiple types of charge controllers can be used with SLA batteries; among the listed batteries, the easiest and least expensive to charge via solar
Lithium-Ion (Li-ion)
Without a doubt, lithium-ion batteries have revolutionized the consumer electronics world.
Why are they so popular?
First of all, their construction allows for a variety of form factors ranging from cylindrical cells to slim packs and pouches so thin they can fit in an ultra-thin mobile phone, eReader, or tablet. They’re the easiest type of battery to accommodate in compact consumer electronics, and indeed, they power most of the consumer electronics we’ve put to use in the last decade.
Secondly, they have a very high energy density, thus pack a lot of capacity for the size and weight. Indeed, if size and weight are your primary requirements, li-ion batteries should be high on your list.
In addition, Li-ion batteries are ubiquitous and affordable because they’re used in so very many applications.
There are negatives, though, with these power sources. First and foremost, they’re very sensitive to over-voltage and over-current events that initiate a thermal runaway. To prove this point, I’ll share some first-hand experience from the early days of large lithium-ion packs…
Li-ion Horror Story
In 2011, I evaluated a lithium-ion battery pack with integrated 5V USB chargers and even a simple one-outlet inverter from one of the big names in portable power systems. At the time, this was a new battery pack and a relatively new technology, at least in terms of the energy density and compact size. After receiving the battery, I charged and discharged it perhaps twice during testing. I had a flight scheduled from North Carolina to California, and decided I’d take it in my carry-on bag to power my laptop in flight. It worked fine on the flight to KSFO. Once there, I recharged it. On my return flight, it simply didn’t work. I thought perhaps I hadn’t plugged it in properly, or that the hotel outlet I used didn’t work. Upon arrival I emptied my travel pack onto the bed and plugged in the battery pack; it indicated it was taking a charge.
After doing a few projects around the house, I went back up to the bedroom and was greeted with an overpowering smell––almost like the pungent chemical odor of nail polish remover. I looked everywhere for the source of the odd smell. Finally, I located it: it seemed to be coming from the battery pack. Upon examination, I could tell the battery had begun to swell. As I lifted it up, I noticed that the bottom portion was essentially in a state of melting. As quickly as I could, I unplugged it and removed it from the room. I then discovered that in the thermal runaway process, it had begun burning through the sheets and mattress of the bed. Shocked, I suddenly realized it could have burned down my home.
Keep in mind, I was completely new to this battery technology, and this was years before thermal runaways made the news and airlines began restricting their transport. To my relief, the company from which I purchased the pack ended up pulling that model off the market, and even reimbursed me for the mattress and bedding. But it was a hard lesson learned.
If I’m being perfectly honest, this lesson had a major impact on my willingness to experiment with Li-ion battery packs.
The problem with the model of pack I had purchased was not the battery chemistry or construction, per se, but the charge controller). The fact is, Li-ion batteries require millivolt accuracy and a number of protections to detect and stop thermal runaway. Battery packs with multiple cells need a battery management system (BMS) that also balances the cells and monitors them closely. Fortunately, most manufacturers of the technology now understand this.
Modern Li-ion cells and chargers are much safer and more stable
Since then, Li-ion battery chargers have become both orders of magnitude safer and more effective. Still, I only charge these batteries on a surface which, should the battery be tempted to melt down, would be less likely to be damaged or serve as a fire hazard. I also never leave them unattended during charging.
With that said, I don’t think Li-ion batteries are to be feared. Obviously, many of us walk around with one tucked in our pocket all day––in our smartphones! They’re generally considered very safe now. Of course, I’d only buy the best and would steer away from the lowest-costs units you might find on eBay and Aliexpress, as many of these products are made in places with little oversight or regulation.
Another interesting fact about Li-ion battery packs is that since their voltages are usually available in multiples of approximately 3.6 volts (e.g., 3.6, 7.2, 10.8, 14.4 and 18 volts), they are not always ideally suited for radios that require 13.8V input power. Some packs, however, have circuitry that provides an output voltage closer to your desired amount.
One Lithium-ion battery pack I’ve been using with my Mountain Topper MTR-3B, Elecraft KX2 and KX3 transceivers is a (very affordable) TalentCell rechargeable 3000 mAh Li-ion battery pack that provides both 12V and 5V USB power. It has built-in charging circuitry and is very compact. I purchased mine for about $25 on Amazon.com, and have been very pleased with it so far.
Summits On The Air operators often place priority on smaller-sized and lighter-weight power sources, and thus turn to Li-ion battery packs. Many SOTA friends have invested in high-quality balance charger/dischargers to maximize the life of their batteries, and have been happy with the performance they receive. A quality charger may costs upwards of $60, but is worth the investment if you choose Li-ion batteries as your portable power of choice.
Price: From affordable to pricey, depending on capacity and charger investment
Weight: The lightest weight portable battery options in this list
Voltage: Often in multiples of approximately 3.6 volts: (3.6, 7.2, 10.8, 14.4 and 18VDC)
Longevity: Good. Typically around 400-500 charge cycles if properly maintained
Ease of recharging: Simple, if a self-contained pack; more complex, if using multiple cells that need balancing
Solar charging option: Not advised (yet). There are a number of homebrew Li-ion solar charging projects on the web, but I believe this battery chemistry fares better with a balance charger connected to a stable AC power supply.
Lithium Iron Phosphate (LiFePo4/LFP)
I typically use my 15 Ah LiFePo4 battery pack when powering transceivers like the Mission RGO One that can push 55 watts of output power. I also use this battery to power my Elecraft KXPA100 amplifier on Field Day.
The final type of battery chemistry we’ll cover here is my favorite of the bunch.
There are good reasons why Lithium Iron Phosphate batteries have become one of the choice rechargeable batteries for field radio use.
LiFePo batteries are inherently stable and safe
They offer a longer cycle life than that of other Li-ion, NiMH, NiCad, or Lead Acid batteries–thousands of charge cycles as opposed to hundreds
LiFePO batteries have an excellent constant discharge voltage
LiFePo batteries use phosphates––as opposed to cobalt or nickel, which are supply-constrained and carry heavier environmental concerns
LiFePo batteries have a lower self-discharge
LiFePo batteries are very lightweight compared to SLA batteries
3.2 V nominal output voltage means that four cells can be placed in series for a nominal voltage of 12.8 V, near ideal for most field radio gear
Any cons? Yes…while they’re lightweight, LiFePo4 batteries aren’t as compact as Li-ion battery packs. But the primary negative here is the price. At time of print, LiFePo4 batteries have the highest cost per Amp hour of the batteries discussed in this article. With that said, due to the excellent longevity of these batteries, the LiFePo may be the most cost effective option in the long term.
LiFePo4 battery systems sport built-in battery protection modules to address concerns like over-voltage and balancing.
How do LiFePo batteries stack up?
Price: One of the pricier options, when you include the battery and charger
Weight: Very light weight, but size tends to be larger than comparable Li-ion packs
Voltage: Excellent match for gear requiring 12V – 13.8 VDC
Longevity: Excellent. Thousands of charge/discharge cycles
Ease of recharging: Simple, using the provided charger (battery packs have a built-in charge controller)
Solar charging option: Bioenno sells charge controllers designed to work with LiFePo batteries, handy for the field
Without a doubt, the best-known LiFePo battery manufacturer in the world of ham radio is Bioenno Power. I’ve purchased their batteries exclusively and have been incredibly pleased with the quality, longevity, and performance of their products.
Choosing the right battery for you
Each one of these battery types have their pros and cons, and you can find lengthy, in-depth discussions online about the nuances of each battery chemistry. At the end of the day, however, what matters is which one best suits your particular application and provides your gear with the appropriate amount of voltage.
Here’s when I would reach for each of our types of batteries…
NiMH LSD AA batteries
WD8RIF uses Eneloop rechargeable AA batteries with his Elecraft KX3 field kit (Photo: WD8RIF)
If you’re willing to use a battery pack to run 8-12 cells in series to achieve your required nominal output voltage, Eneloop batteries are relatively affordable, lightweight, and of course, power an array of electronic devices in our world.
Of course, AA Eneloop batteries are also invaluable for those of us who have an arsenal of portable shortwave radios that accept AA cells!
Sealed Lead Acid Batteries
If you’re on a very tight budget and weight is less of a concern, SLA batteries are a great choice. They’re an especially affordable option if you plan to make a solar-powered battery pack since charge controllers are quite simple and affordable.
If you’re looking for a stationary back-up battery for home, these are an excellent choice, as long as you keep the charge topped up.
Li-ion Batteries
Backpacking or flying overseas, and size and weight really do matter? Purchase a Li-ion battery system. Li-ion cells and packs offer the highest energy density of any of the battery chemistries in this list. They’re incredibly compact––and as long as you use a quality charge controller with built-in protections, and you don’t damage or puncture an actual Li-ion pack––they should be quite safe, and you’ll be pleased with performance. Note: Keep in mind some airlines have regulations about the size of Li-ion battery pack you’ll be allowed to carry on board, so do check before departure.
LiFePo Batteries
The 9V 3Ah Bioenno LiFEPo4 pack is very compact and pairs beautifully with the Mountain Topper MTR-3B as this particular transceiver prefers voltages at 12 volts and below.
If you’re looking for a simple, effective portable battery solution that is almost custom-designed to power radio gear, invest in a LiFePo4 battery and charger. I have everything from a 15 Ah 12V LiFePo4 battery that can power my 50 watt Mission RGO One transceiver, to a 3 Ah 12V pack I now use for 2-3 hours in the field at a time with my QRP transceivers. Bioenno has recently sent me a 9 V 3 Ah battery pack to test with my Mountain Topper MTR-3B––it’s incredibly compact, since it only needs three 3.2V cells in series. LiFePo batteries are also the ones I suggest for those who are new to the world of battery packs and want something that is hassle-free and simply performs.
I admit, I’m being transparent here about why I own a total of three LiFePo4 batteries from Bioenno Energy––they’re amazing and I know I can rely on them.
In summary…
…I would offer this final piece of battery-usage advice: whatever you do, don’t “cheap out” on your battery and charging system. No matter what chemistry you decide to purchase, buy the best quality you can afford. If using any variant of a Li-ion battery, heed my tale, and be sure any separate charge controllers you employ will protect your battery (and your home)!
And now…Go out there and have fun. I assure you: when you take your radios––whether portable shortwave radios or ham radio transceivers––to the field, you’ll find you can escape all of the noises that so often plague us indoors. And out there, you, too, may find your radio bliss.
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