Everyone loves, and should respect, lithium-ion batteries. They pack a ton of power and can...Most new hams start with an HT (handie-talkie) radio. Theyβre very affordable, portable, and will get you on the air quickly. No one has to think about batteries and chargersβtheyβre almost always included. The only real decision is whether you want to buy a spare battery.Β
Going mobile doesnβt take a lot of thought either. You find a place for the radio and remote head, then follow your car manufacturerβs recommendation for power connections. Technically the battery isnβt free, but you already have it.
However, when it comes to field operations like POTA, SOTA, and all the other OTAs, you should consider several factors before investing in a portable battery system. Things like weight, size, durability, and capacity become important considerations.
Power for portable operations can come from various sources, like generators, solar, wind, and batteries (the primary choice of portable operators). Lithium-ion (Li-Ion), sealed lead acid (SLA), gel cell, and absorbent glass mat (AGM) are among those available.
However, the most efficient battery choice is a member of the lithium-ion family, LiFePO4 (lithium iron phosphate).
LiFePO4 is superior to other lithium-ion batteries for a couple of reasons. Number one is safety. The LiFePO4 chemistry has better thermal stability than lithium-ion. It will remain cool at room temperature while charging, while Li-Ion heats up faster and may potentially suffer from thermal runaway. LiFePo4 battery systems also contain built-in battery protection modules to address concerns like overvoltage and balancing. You probably remember stories about hoverboards whose lithium-ion battery packs began overheating, which led to sparking, catching fire, or melting.
The voltage supplied by a LiFePO4 is a good match for todayβs radios.
Each fully charged cell produces 3.6V. With four cells in series (4S), a typical LiFePO4 battery pack comes in at 14.4V. The nominal voltage is 3.3V per cell, making the working voltage about 13.2Vβan excellent choice for a typical 100W transceiver.Β
Li-Ion/LiFePO4 batteries maintain a flat voltage curve compared to sealed lead acid or absorbent glass mat batteries, which start dropping voltage right from the beginning. SLA or AGM runtimes will be considerably shorter than a comparable Li-Ion or LiFePO4 battery.
Though people still buy lead-acid batteries because of their low prices, LiFePO4 is a better bargain in the long run. When you consider the lifespan of each type of battery, the LiFePO4 will last more than 12X longer, yet only costs 3-4 times the price. Lithium batteries will also hold a resting charge much longerβLiFePO4 is typically rated at 5% discharge per month.
Each one of these battery types has its pros and cons, and you can find in-depth discussions online about the nuances of each battery chemistry. However, what matters is which best suits your particular application and provides your gear with the appropriate voltage and operating time. If youβre looking for a simple and effective portable battery solution almost custom-designed to power radio gear, invest in a LiFePo4 battery and charger.
Everyone is looking for maximum operation time in the smallest package. SLA, gel cell, and AGM batteries will do the job but have drawbacks for portable operation, especially with weight and available power.
I suggest that those new to these battery packs look for something that is safe, hassle-free, and performs well. The battery management system built into the lithium batteries avoids the βoopsβ factorβit wonβt let you draw more than their rated capacity.
For that reason, the lithium-ion batteryβspecifically a LiFePO4βis a no-brainer, especially the Bioenno Power line.
For example, Bioenno Powerβs BLF-1220A LiFePO4 Battery is ideal for stationary applications requiring a higher capacity and greater power output.
The integrated PCM (Protection Circuit Module) provides complete internal cell balancing and management, protection from overcurrent, undervoltage (over-discharge), overvoltage, and short-circuiting, as well as integrated charging circuitry. As shown above, the BLF-1220A can also be purchased as a combo with a 14.6 VDC charger.
Itβs easy to find various lithium-ion batteries online with a casual search. The problem is that you can quickly become overwhelmed by all the choices. I consulted with several hams who have experience with portable operation and got some excellent advice.
When you buy, be sure you have the proper charger for LiFePO4 batteries. Some come in battery/charger combos like the above example. SLA chargers are NOT compatible and may damage a LiFePO4 battery. Whatever you do, donβt compromise on your battery and charging system.
The following will help you get a better understanding of your battery needs and help you narrow the options.
Your radio doesnβt demand a consistent amount of power; rather, it varies according to the transmit time, receive, and transmit modes used. According to the Yaesu FT-891 mobile transceiver manual, the receive takes about 2W while the transmit may take as much as 23W. Sideband will draw less power than a continuous mode like FT-8 or RTTY.
Weighted averages will give you a better picture of power consumption.
(x) * (power 1) + (1-x) (power 2)
Example
20% of time transmit at 100W
80% of time receive at 2W
0.20*100 + 0.82*2= 21.6Β
11 hours of run time on 20 Ah LiFeP04 ([12v x 20 Ah]/21.6)
Donβt forget to account for accessories such as portable tuners.
Inline DC Power Analyzers and wattmeters allow you to measure and monitor the DC power consumption of your portable equipment. These DC power meters read voltage, current, watts, amp/hours, and watt/hours. Theyβre connected between the power supply and radio to help you monitor power consumption.Β
You can also utilize these as part of your portable OTA gear, which gives you real-time information about your batteryβs state while operating.
Bioenno mobile transceiver compatibility guides cover the most popular radios. They are available on the DX Engineering website at the links below.
In addition, Bioenno provides battery runtime charts for all their models
The post Ham Radio Tech: Choosing a Battery System for Portable Operations appeared first on OnAllBands.
Everyone orders off the same menu. Anyone who has not been living under a rock since the pandemic knows full well that pretty much everything is getting crazy expensive. That would be bad enough except very few of us have increased our income accordingly. This is not a political statement.... Read more Β»
The post Is Inflation Making Off Grid Power Too Expensive? appeared first on Off Grid Ham.
Power. It is one of the most important aspects of running an operation. But what if you donβt have access to AC power or a storm knocks out all power in your area? Β
There are some differences if you are at home or in the field. At home you will want to power more than just a radio and its accessoriesβthings like a refrigerator, air conditioning, and internet service.
What you want is an uninterruptable power supply (UPS). These can be as little or as large as you can afford. Most of us have small units connected to our computers for safe shutdown. There are room size UPS units that back up large data centers, hospitals, and other critical infrastructure.
The big question is how much runtime do you get? This is almost solely dependent onβ¦
β¦you guessed it. Batteries.
Lead-acid batteries, most often deep-cycle, are a good choice for emergency power. They are rugged and have relatively low energy density. The deep-cycle option also handles a slow discharge well. They can be used with or without a battery box. A battery box can be purchased or homemade. The cost is on the lower side for batteries as well. The main disadvantage is that they can be extremely heavy, which is usually not an issue for home use.
The next option for home use is a generator, like the Generac GP3600 Series Portable Generator shown below. These can provide power for an extended time period and are rugged. However, generators are bulky and not easy to move. You also need to have fuel to power them and keep them running smoothly.
Solar is a good choice for home and portable use. It also has the advantage of being environmentally friendly. A solar cell, or photovoltaic cell (PV), is a device that converts light into electric current using the photovoltaic effect. Multiple solar cells are connected inside modules and modules are wired together to form arrays. The arrays are then tied to an inverter, which produces power at the desired voltage.
A large array for maximum power can become very expensive. Home solar systems often have a way to store excess energy and feed it back into the power grid. Portable solar panels come in many shapes and sizes that you can roll up, fold up, or fold over for easy storage. Straight panels that are more rigid are a good option as well.
Youβll find several solar power options at DXEngineering.com, including Bioenno Power foldable solar panels and solar charge controllers, and the Samlex Solar Portable and Foldable Solar Battery Charging Kit below.
So, what are some good options for people out on a field exercise or during a Parks on the Air activation?
A choice that is growing in popularity is a power station, like the A-iPower 300W Lithium Portable Power Station below. It includes outlets for USB and 12-volt power, with receptacle plugs for easy hookup and power supply. While power stations are relatively lightweight, they may not be the best option for tossing into a backpack from a weight perspective.
Another extremely popular option is the lithium iron phosphate battery. Lithium iron phosphate (LFP) is an inorganic compound with the formula LiFePO4. Some of its advantages include long cycle lifetimes, high power density, wide operating temperature range, and easy transportability due to its light weight. You can find a range of Bioenno Power LiFePO4 12VDC batteries (see the 12 Ah model below) and battery/charger combos at DXEngineering.com.
What is your favorite alternative or backup power? Questions?
Share them in the comments below or email me at KE8FMJ@gmail.com.
The post Backup Power for Home & Field appeared first on OnAllBands.
During the middle of the night on Saturday/Sunday, I got a low battery voltage warning on the KX3. That struck me as odd, as I had recently charged up my 12V 10 Ah battery. I was expecting it to last the entirety of Field Day.Β But in the heat of battle you really don't think twice about it, so I took it off line and hastily replaced with a recently purchased 12v 5 Ah battery that I had gotten about two weeks ago. THAT battery lasted the second half of Field Day without a whimper.
When I got home from work on Monday, I put the 10 Ah battery on my charger and was getting a battery failure indication. It was reading at a level of 10V and 0% capacity and would not accept a charge, I was wondering how can this be? It was purchased new and I haven't put it through nearly enough cycles to have exhausted it. I figured it must be a battery charger fault, so I hooked up the 5 Ah battery to the charger to see what it said. The 5 Ah (which was in use for roughly the same amount of time, if not more) was down to only 11.8 Volts and had 89% capacity left in it! And the charger's fan started running as soon as I hooked it up.
No charger fault - I got a bad 12V 10 Ah battery. Dang!
I don't remember where I purchased it, whether it was from eBay or Amazon, but it doesn't matter. Its not like you can return a battery some 11 months after you've bought it online. I had purchased it after the 2023 Skeeter Hunt when my last deep cycle battery gave up the ghost. I don't want to be scrambling for electrons during the Hunt this year, so I went on eBay and found an economically (cheaply) priced 12V 10 Ah Deep Cycle Gel Cell battery.
I know, you guys are probably thinking, why didn't he go lithium?Β Price mainly, but also because I don't feel like purchasing a dedicated lithium battery charger. I once ruined a small lithium battery by not using the correct charger on it and I don't want to relive that escapade. I learned that lesson well. However, should this battery not last longer than a cycle or two, I guess I'll bite the bullet. Maybe spending a little more right now would be the right thing to do in the long run, but I guess I'm too frugal to have reached that point yet.
It should be at my house in about a week - long before it's needed for the Skeeter Hunt on August 18th - which, by the way, we've had 93 sign ups so far and the 1st Day of Summer was only 6 days ago!
And looky see what came in the mail yesterday!
Not an ATNO, but an ATNC - All Time New Confirmation. I've worked Easter Island before, but never got a QSL card.
72 de Larry W2LJ
QRP - When you care to send the very least!
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The post Batteries: Your Weakest Link. appeared first on Off Grid Ham.
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The post Lithium Batteries In The Cold: A Guide. appeared first on Off Grid Ham.
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