Off Grid Ham: When Your Batteries Are Boiling

Chris at Off Grid Ham has an article up, talking about the danger/effect of heat on your batteries. When Your Batteries Are Boiling

Most of the USA is going through a blazing hot summer! Here in the upper Midwest it’s been over 90F/32C every day for almost two weeks. As I write this it’s 87F/31C in Buffalo, New York. That doesn’t sound too bad until you consider that it’s past sundown there, and the average daily July high for Buffalo is only 80F/27C. Most off grid amateurs fuss about battery temperature when it’s cold. Have you ever thought about what heat does to batteries? If you haven’t you should.

The chemistry of heat. battery temperature

How heat effects batteries varies greatly depending on the type of battery, how it is used, and the current going into/out of the battery. Battery chemistry, which is quite complex, is made even more complex by changes in temperature.

In addition to ambient heat, batteries themselves generate heat when they are charged or discharged. So, we have two factors at play. The radio amateur has only limited control over these two factors. Managing heat, to the extent that you can, will give your batteries better performance and a longer service life. battery temperature

Lithium batteries. battery temperature

Few things have benefitted amateur radio like lithium batteries. They are so much lighter and more powerful than their predecessors that the step forward in technology can plausibly be compared to when the transistor replaced the vacuum tube.

But like their ancestors, extreme temperatures effect lithium batteries. Once a lithium reaches 113F/45C, it should not be charged because excessive gas buildup can cause a cell to bulge. Lithiums can be discharged at up to 140F/60C but will lose capacity as they reach the upper limit of their operating range. There is also evidence that the higher the beginning state of charge, the more capacity will be lost as the battery heats up.

All larger lithium batteries have an on-board battery management system (BMS) that controls charging and cell balancing. Usually these electronics will reduce the current or not let you charge or discharge at all outside of acceptable temperature parameters. The high limits may seem generous, but do not underestimate them. Leaving a battery in a car on a hot summer day can easily push it beyond 113F/60C. If you are operating outdoors on a hot day and connect a solar panel to your lithium battery, the ambient temperature plus heat generated by the charge has the potential to exceed established temperature limits. The bottom line is, if your lithium batteries do not already have temperature-compensating circuitry, then you’ll have to monitor battery heat yourself.

AGM/Sealed batteries.

AGM, sealed lead acid, and gel cell batteries are cousins of each other and share similar characteristics. They’re very popular with amateurs due to their relatively low cost and ease of use. battery temperature

The top operating limit for AGM/SLA/gel batteries is 120F/49C. Like lithiums, AGM batteries will have reduced capacity at high temperatures and can also bulge/expand out. Thermal runaway is rare but possible. Overcharging generates heat and AGM batteries are especially sensitive to overcharging, so radio amateurs should be attentive when charging these batteries. A “smart charger” with a temperature probe would be ideal.

AGM-class batteries should not be discharged to less than 50% full. This presents a problem because they lose capacity at high temperatures. So if you have a battery that already has diminished capacity because it is hot, and then have to observe a 50% floor, that doesn’t leave much useful power for your equipment. At the same time, you will have to reduce charge current to avoid further overheating. The end result of all of this is a battery that will need to be charged more often and for longer periods. In a hot environment your AGM battery will for all practical purposes have less than half of its rated capacity. Lastly, long term exposure to heat will cut the service life of an AGM battery by half for every 15F rise above 77F (source)…

Click here to continue reading at Off Grid Ham.

OH8STN: Emergency Power for Communications

Amateur radio enthusiast, blogger and vlogger OH8STN (Julian) has posted the second video in his Grid Down Communications series. In this video he addresses peoples’ concerns with how they will keep their communications online when the grid is down, including batteries, solar generators, solar panels, and other alternative power.

OH8STN: Grid Down Communications for Preparedness

Amateur radio enthusiast, blogger and vlogger OH8STN (Julian) has posted a video on Introduction to Grid Down Communications for Preparedness. As he says, planning for a grid down scenario covers around 99% of the scenarios that a person may face (earthquake, pandemic, civil unrest, etc.) Julian covers a lot of useful information in the video, not just for amateur radio operators but anyone trying to prepare to communicate in such a scenario.

Here is the first video of the series:

Related:

Suggested Radio Equipment for Community Safety – but there is no “one size fits all” communications solution as pointed out in OH8STN’s video above. Julian’s video discusses some of the assumed background information of this article in more detail. This article discusses the equipment that is working for the LVA.

Brushbeater: Tasks for the Designated Commo Guy

If you’e the person who has been put in charge of communications for your group, NC Scout at Brushbeater blog has an article up outlining the basic tasks that you should be working on – Tasks for the ‘Designated Commo’ Guy.

…that’s where the challenge of the designated guy begins- competently training your people to that baseline.

First things first, you can never, ever expect to get anywhere if you fly so far over people’s heads they ignore you. Members of your group have to see the relevance in what they are doing or else its a doomed effort from the get-go. With communications, the tendency is for new people to get quickly overwhelmed and all of them are explicitly not looking for a hobby, they just want their equipment to work. If they didn’t have interest in communications before, chances are very high there’s an end goal in mind and its not experimentation. They want validation that whatever this was they spent hard-earned money on based on your recommendations actually does what its supposed to do. What you told them it would do. And if they don’t see the results, you’ve got an albatross around your neck. Everything begins with the basics. As we used to be told over and over again, there is no such thing as super-duper secret techniques, just mastery of the basics. And I’ve found that to be true of nearly every task in life- what might seem rudimentary to one guy might be a tough task to another; the goal is to build everyone up.

#1. Create a Local Network

The first big hurdle to cross is to establish communications among your people. Not in the tactical sense, but in the practical sense. Realistically, your neighbors and people who live within about a 30 minute drive are what you have access to as far as people go- should the balloon go up tomorrow, they’re the ones who matter…

Edit: NC Scout posted an update article based on questions that were sent in about the article above, Practical, Tactical: Training Questions from a Reader.

I got these questions from a reader based on the last couple of posts and its questions many have but don’t quite understand. There’s a lot of different reasons people begin to focus on communications, but when you boil it down, its one of two real necessities: either networking your group over an area, or, supporting tactical needs. The two goals are different, and while there’s some overlap, its a different mission set with different techniques.
I’ve began reassessing communications needs because like you said in an article recently, I as a ham have been ignoring the benefits of using non-ham comms somewhat.
This is a really common attitude. A lot of folks forget the advantages of license free options once they get a ham license. The thing about amateur radio is the great pool of resources and nearly unlimited options you’ve got on the table. But not everyone in your group is going to get up to speed or even look into a hobby- it’s easier to defer to you, the subject matter expert, and do whatever you help them set up or suggest. Which normally means going license free.
I feel like there is a line between too little radio comms and too much though. I’ve always thought of it as a team leader and up sort of equipment, I.E. not every rifleman needs a radio. Even then, you still probably only need one radio that’s capable of communication outside the general area of the squad, in order to send reports etc. But on the flip side, in a MAG type setting, people need to be able to communicate with each other as well. So if you were to use FRS radios for your local non-tactical nets, wouldn’t that exclude them from use in a tactical situation? And then also GMRS as well, since it’s basically the same chunk of spectrum as FRS? And I don’t like the idea of relying on MURS with only 5 channels for tactical comms, although it would be simple. So other than CB, which is also channel based, I think I’m out of non-ham options, please correct me if I’m wrong though.
And this is getting into the heart of the question. There’s definitely a line between too much and two little, and it all revolves around the mission…

Brushbeater: Commo Tips for New Groups

NC Scout has an article up at his Brushbeater blog on communications tips for new preparedness groups, mutual assistance groups, or other groups needing radio communications – Commo Tips for New Groups.

I had the incredible experience of being a guest on authors Glenn Tate and Shelby Gallagher’s Prepping 2.0 podcast and radio show, and along the interview we covered common issues that I see a lot of preppers just getting into communications have. Since I’ve been running classes for over three years now getting people up to speed, there’s a several issues I see repeating over and over. But fortunately in every case, the answers are more simple than you think.

Understand Your Real Needs

I always point folks to their primary needs- creating local infrastructure. We can’t really control much outside of our primary Area of Operation (AO) or Area of Influence (AI), but what we an do is work to build up local infrastructure within those areas. And if that’s all you can do, but you’re actively doing it, then you’re lightyears past what others are doing. This means VHF and UHF capabilities, which are both very common and pretty inexpensive for basic equipment.

What should I buy?

This is the first question most people ask. Its the same with guns, trucks, tires, and anything else you can spend money on. The answer I come up with in class is that its not the equipment, its the capability; that means frequency ranges. That $25 Baofeng UV-5R operates on VHF and UHF frequencies, both licensed amateur (ham) and license free (MURS, FRS, etc)…

Click here to read the entire article.

AmRRON Goes to AMCON 2 for Hurricane Florence, 9-13-18

As of Thursday, 13 Sept. at 1700hrs Zulu we are increasing the AmCON to level 2 (Incident Imminent). Hurricane-force high sustained winds and extremely heavy rainfall are forecast and damage is imminent. Major disruptions to conventional power and telecommunications grids as well as transportation are expected in North Carolina, South Carolina, and Georgia, especially along the coastal areas.

As of this update, persistent (continuous) nets are being conducted on the 40m and 80m digital frequencies using beaconing modes FSQ Call and FT-8 Call. Additionally, nets are being conducted according to the AmRRON SOI. Please refer to the AmRRON Activation PDF for more details.

Expect a change to AmCON-1 (Active Incident) within the next 6 to 8 hours.

Click here to read more at AmRRON.com.

Edit: AmRRON went to AmCON 1 on Friday, September 14th, 2018 at 0300 zulu.

Edit: AmRRON returned to AmCON 5 on September 17th, 2018, while continuing to support operations as needed.

Amateur Radio Prepares for Hurricane Harvey

From the ARRL, Array of Amateur Radio Resources Readying for Hurricane Harvey Response:

Amateur Radio resources are marshaling to assist in the response to Hurricane Harvey, which is expected to make landfall along the Texas coast on Friday (August 25) as a Category 3 storm. It would be the first storm to hit the US coast in more than a decade. The Hurricane Watch Net (HWN) already has swung into action, as the storm, which bears the threat not only of high winds but extensive and life-threatening storm surge flooding. Nearly 3 feet of rain could fall, if, as predicted, Harvey stalls along the Texas shoreline. ARRL Emergency Preparedness Manager Mike Corey, KI1U, said he and his staff are keeping close watch on Hurricane Harvey.

Hurricane Watch Net

The Hurricane Watch Net activated on August 24 at 1500 UTC on 14.325 MHz, subsequently shifting to 7.268 MHz at 2300 UTC. The net planned to operate overnight and will resume daytime operation on 14.325 MHz at 1200 UTC. “Should band conditions dictate, we will operate both frequencies simultaneously,” Net Manager Bobby Graves, KB5HAV, said.

Click here to read the entire story

Click here for ARRL Texas incident plans for Hurricane Harvey, including HF, VHF, and UHF frequencies. There are many frequencies in the plan.

Related:

Harvey Regains Strength, Hurricane Watch Net Plans to Activate

National Hurricane Center – Harvey

Weather.com – Hurricane Harvey

AmRRON Advances to AmCON 3 – Aug. 8, 2017

Today, AmRRON announced that it had moved the organization to level AmCON 3.  Level 3 means that an incident is considered probable which would interrupt conventional communications, but not necessarily imminent.

*08 AUG 2017 UPDATE: *

Due to the increased probability of armed conflict with North Korea,
which is now nuclear-capable and could strike American cities on the
mainland, we are increasing our readiness levels and the AmRRON
Readiness Condition Level to 3. This means that while disruptions to
conventional communications are by no means imminent, there is an
increased probability.

https://www.cnbc.com/2017/08/08/trump-warns-north-korea-threats-will-be-met-with-fire-and-fury.html

Trump warns North Korea threats ‘will be met with fire and fury’

* President Donald Trump warns that threats from North Korea “will be
met with fire and fury like the world has never seen.”
* North Korea has successfully created a miniaturized nuclear weapon
that can fit in its missiles, according to NBC News and The
Washington Post.

*Note from JJS: * This is significant. President Trump is warning that
these continued threats must stop and that he is prepared to carry out
military action. Previous attitudes and responses indicate that North
Korea will continue to agitate the US and other nations. Essentially,
Trump must make good on his word. If he does not, it will only embolden
North Korea and increase the danger to US citizens and interests, as
well as our allies. Essentially, it appears the time for talking and
negotiating are over. We’ll see. Boy Scout’s motto: “Be Prepared”

————————————

*Additionally, the previous open source (OSINT) information which
prompted us to raise to Level-4 several weeks ago is still relevant:*
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