Using Emergency Backup Power -- When the Lights Go Out!
A second power cable for your radio. Since these cables are becoming more standardized with "T connectors", they are available at many radio shops.
Large size Deep Cycle Battery. A "27 size" works well. Deep Cycle batteries are important as they can be repeatedly charged. Regular automotive starting batteries are not as good. They don't hold the consistent power for our application and repeated recharging can shorten their life span.
A combination "Float" and "Trickle" charger. This is a very important part of the project. The float type chargers maintain a topped off level for the battery without creating a lot of "out gassing", which could be an irritant inside the home. They also don't deplete water the same way a conventional charger can. Proper use of a float charger can maintain the life of a deep cycle battery for years.
What to do: Start with a fully charged battery and keep it in the ham shack with the battery half of the extra power cable attached to it. Then, wire tie the half of the power cable right next to the "T" connector on the primary power cable. This puts the two "T" connectors beside each other. When the AC power goes out, simply unplug the radio half of the power connector from the normal power supply "T" connector and plug it into the battery side duplicate "T" connector and you are now running on backup power!
by VK4DGG on March 12, 2006 Mail this to a friend!
I am a US Ham now living in Australia. I was a Ham in North Carolina for years before moving here. My shack is capable of a couple of weeks of operation on reduced power by my estimate, especially if I reduce my HF power to about 20 watts. My main rig is a Kenwood TS2000, I have a second base/portable rig, a Yaesu FT897. I have a Icom 706 MKII mobile and a FT817. I have a mix of Yaesu, Icom, Kenwood and Alinco dual band handhelds. I can hit a total of 12 repeaters from my QTH on VHF/UHF with very modest antennas at 20 feet and 5 watts with the handhelds . I have 600 amp hours of SLA battery backup on the shack floor. I have a small generator and a 40 watt solar panel with charge controller. I keep the SLA's topped up with a mains powered charger. I hate to say this but(knock on wood), there seems to never be any emergency situations in this neighborhood of Australia, not like Eastern North Carolina (Bertha, Fran,and some guy's name I can't remember). Well, I will keep everything topped up......just on case.
by KG4RUL on March 12, 2006 Mail this to a friend!
" I can hit a total of 12 repeaters from my QTH on VHF/UHF with very modest antennas at 20 feet and 5 watts with the handhelds ."
Scene shifts to Katrina. "I can't hit any repeaters from my QTH because, they no longer exist."
We need to learn, and regularly practice, how to operate in a simplex enviroment. That means formal net procedures and traffic relays.
All the backup power in the world is of little use if you release the PTT and nobody comes back to you.
Or worse, the person who comes back has no idea at all of how to interact with the nets. At this point, OJT is not a good thing.
by LNXAUTHOR on March 12, 2006 Mail this to a friend!
- i just wish that manufacturers would bring new lower power portable rigs to market... i guess for now we'll have to rely on QRP kit rigs (Elecraft, Wilderness Radio, Small Wonder Labs, etc.)? even the Yaesu FT-817 requires .5Ah for receive!
- still, i'm grateful for what i have, and glad i have my FT-817 and two SGC SG-2020s!
by NA4IT on March 12, 2006 Mail this to a friend!
AND 706 MKIIG, on as needed.
by K0BG on March 12, 2006 Mail this to a friend!
There really isn't much difference in the charge life cycle of a deep discharge and that of an SLI (plain old car battery). The major difference is the voltage point when fully discharged.
An SLI is typically considered discharged at 11 volts, and most deep discharge ones at 10.5. In either case, taking the battery below this level will shorten its life.
When batteries are located in non ventilated areas (inside a home), AGM or Gels are much better choices than flooded types. Aside from the liquid electrolyte hazard, the out gassing is considerably less.
by K5LXP on March 12, 2006 Mail this to a friend!
That's quite a different way to look at it, Alan. From a practical standpoint what good is having an SLI battery that can provide 500 cycles @ 10% DOD, providing just a handful of Ah vs a deep cycle that can do the same 500 cycles down to 20% SOC, and dozens of Ah? The answer is to keep your starting battery in your car, and your deep cycle batteries on your radios.
I would not keep a flooded battery in the house. They are constantly venting acid fumes that will settle on everything around the battery. Even in the garage, I've had metal tools rusted very quickly in the vicinity of stored batteries. I would keep a flooded battery on a float charger where there is plenty of ventilation, then if standby power is needed, bring it into the station.
The most practical way to deal with all of this is to use a large computer UPS, containing sealed gel or AGM batteries. The UPS takes care of all the charging, the batteries do not pose any venting issues, and the power switches from AC to battery seamlessly and instantly. No fumbling with reconnecting power cords, and everything still works- PC's, antenna rotators, wall warts to charge your HT, etc. I bought my 1kW UPS at a fleamarket for $75, plus a new set of batteries. I also have a marine battery on standby (in the garage) should the need arise but I have yet to encounter an outage the UPS couldn't ride through. For really long term standby power a generator is a necessity, batteries only take you so far. But that's the topic of another article.
by K4RAF on March 12, 2006 Mail this to a friend!
"...how to operate in a simplex enviroment. That means formal net procedures and traffic relays."
by W5HTW on March 12, 2006 Mail this to a friend!
Then, of course, if you want to see what NON-control of a net is like, watch "The View" on ABC TV for two minutes. (If it doesn't give you a stress attack.) Five women plus a guest all talking at once. No one is understood and it's just noise.
However, I'm all for abolishing net controls, and getting ham radio out of the "business" of pretending to handle any kind of traffic, or offering any kind of support in emergency situations. Let the professionals handle it, and let hams go back to "i'm gonna key down and ain't no one gonna talk onna channel."
by W3JKS on March 12, 2006 Mail this to a friend!
A tip on using computer UPS systems with generators. Many generators, especially the small "consumer grade" units, do not generate a pure sine wave at 60 Hertz to put it nicely. As a result, some UPS systems (APC and Best are what I have experience in) will balk at using the generator power.
So the generator is purring along, then 15 minutes later you starting getting the low battery alarm on the UPS. You may notice the "on battery" and "off battery" flickering.
Look for a voltage and frequency stability adjustment in the UPS software. It usually defaults to something which is very conservative. You will need to change the settings to a more "forgiving" mode - then you will see that the load goes onto the generator and the UPS battery will begin to recharge.
Most inexpensive UPS systems are what we call "off-line" systems, meaning that the UPS feeds you straight utility power until it senses too much variation in voltage or frequency. When this happens, it starts the inverter and uses a static switch to feed the critical load from battery.
by KV6O on March 12, 2006 Mail this to a friend!
I use a TS-2000 with a 100Ah AGM battery floating across my Astron. I also have a 50AH AGM on a float charger, just in case. I have done deep discharges on both with my West Mountain CBAII so I know what they can deliver - you don't want to find out your batteries have zero capacity when you need them! I also have a 1A solar panel that can charge them if need be... I'll just have to use something a little more energy efficient if things get that bad!
by WA1RNE on March 12, 2006 Mail this to a friend!
"I can hit a total of 12 repeaters from my QTH on VHF/UHF with very modest antennas at 20 feet and 5 watts with the handhelds ."
> "We need to learn, and regularly practice, how to operate in a simplex enviroment. That means formal net procedures and traffic relays."
>>> It just so happens that KG4RUL is absolutely right.
In the aftermath, Florida hams involved in emergency operations concluded that the 2 most useless types of equipment were VHF/UHF repeaters and Packet Radio.
None of the repeaters that were in range could be utilized because their antennas and towers were now scrap metal and/or none had adequate power to run them.
Packet radio offered little in the way of traffic handling during emergency operations or even health and welfare. It was used mostly for updated weather reports or occasional bulletins.
Almost the same deal. Although the antennas were not as much of an issue, most repeaters either didn't have a source of back-up power or the back-up power source didn't stay available nearly long enough.
In addition, when I ran communications for the Town of Burlington, MA Emergency Management Agency and the state Area 1 nets for Eastern Massachusetts (6 months) , I used these examples as "lessons learned".
After Andrew, I changed our SOP, requiring all local cities and towns to demonstrate their ability to communicate with net control via repeater, then switch over to a designated simplex channel and do the same. Stations that had difficulty were asked to enhance their simplex capability and it was re-checked again the following month.
I find it little disheartening when reading the arrogant posts that have "EGO" written all over them, putting down ideas from others that could otherwise be very useful.
The reason?? The "Not Invented Here" syndrome comes to mind, a really nasty egotistical paradox that afflicts many technical and engineering types.
Converting that energy into helpful suggestions would be a breath of fresh air, yes??
by K2WH on March 12, 2006 Mail this to a friend!
My emergency power is simple. I have a single 17.2Ah battery floating on the 12vdc supply. No overheating, no overcharging, no regulation, no nothing. Just alligator clip lead to the DC power strip (fused).
I accidentally shutoff the power supply once and operated HF normally (100 watts) for (2) days before I realized it.
As an experiment, I ran my Motorola GTX 900, 902 mhz for 2 weeks off this battery without interruption. If power is out longer than that then I think its too late for most anything anyway.
by KB1GMX on March 12, 2006 Mail this to a friend!
Myself I structured my station around battery/solar power.
unexpected emergency and planning beforhand. Both count.
larger 100ah (or bigger) SLAs.
used to extend or maintain them.
should be sized even greater by 20 to as much as 4x.
weather and to protect the user.
by KA1MDA on March 12, 2006 Mail this to a friend!
I use 24 2 volt, 660 Ah cells in series for 48 VDC, 660 Ah. These feed a 5.5 Kw (10 Kw surge)sine-wave inverter with built-in 60A transfer switch and 3 state charger. This feeds the entire house, including heating system, radios, A/C, well pump, etc. During power failures, transfer is so fast as to be un-noticeable! Total capacity is around 32 KWh! Keeps everything running for at least 17 - 24 hours, much longer if non-essential loads are disconnected, as would be in case of natural disaster. As a last resort, radio room also has six 12 volt, 25 Ah gell-cells in parallel on constant float charge.
A few years ago, a tree took down power lines 1 hour into June VHF contest- no problem here! Ran full power (100W) on 6, 2, 432, and 10W on 1296 till well past midnight, along with A/C, well-pump, fans, assorted lights, (including outdoor lights at night to tweak neighbors) etc. When power came back on, main battery bank showed 96% full!
by W7COM on March 12, 2006 Mail this to a friend!
A few weeks ago a storm came through and knocked out power for about 16 hours. The solution: deep cycle battery, 12VDC to 110VAC inverter, and CF lamps.. you know, those energy saving compact fluorescent bulbs for your standard lamps? That setup lasted the whole outage with four lamps running (maybe 80w total) with a battery that hadn't been topped-off in months.
Second hint: an old camp stove and hot water bottles. Keeps the bed nice and toasty!
by W3UA on March 12, 2006 Mail this to a friend!
High winds killed AC power to my shack 2 hours before ARRL CW... It was the first time I faced a long power outage (I moved to New Hampshire less than 2 years ago, and my previous power outages never last longer than a few minutes). To be brief, it killed the contest -- I was on the air exactly 24 hours late... Now I have 6.5 KW generator with a few extra gas canisters, proper wiring with automatic trasfer switch, which routes generator power to major life saving cirquits in the house -- water well, central heating, refregirator, computers, and, OF COURSE, radio shack (including 230V for power amplifiers). I run "simulated emergency test", made a few QSO, 1.5KW our, on generator power. There are few minor things -- like my APC UPS, which powers my shack computers and all automation (12V) does not like the quality of power provided by generator, and periodically switches to its batteries -- but overall, other than necessity to refuel the generator every 10 hours or so, everything is same as on mains AC. I can work another contest without help of my utilities company. Although I prefer to have AC, anyway.
The bottom line. Portable AC generator. Don't stay at home without it. If Honda is too steep, then you can buy one for less than $900 at Sam's Club (what I did). No electric starter, but recoil works for me just fine.
by W1RKW on March 12, 2006 Mail this to a friend!
My wife and I live out in the country. It has its advantages and disadvantages. When we moved here a few years ago we found out what the disadvantages were, flakey commercial power. At some point I decided enough is enough and would go with backup power. When I was trying to decide what I wanted to do with emergency power I weighed the options. I decided I didn't want to be bothered with batteries, inverters, solar panels, switches, a mess of wires and what ever else goes along with providing backup power. All I wanted to do is provide some basic power needs like keeping the oil burner going for heat during the winter, hot water 24/7, the frig to keep food and beer cold, the water pump so my wife wouldn't complain about having to use a tree and lights, essentially the basics. So what I ended up with was a backup generator integrated into the home wiring system. So I went big time and it provides me with the everything I need to run the home as if commercial power is available and I wouldn't have to listen to my wife complain and I can still watch TV and play radio if need be. It was well worth the expense.
by KC2MMI on March 12, 2006 Mail this to a friend!
"There really isn't much difference in the charge life cycle of a deep discharge and that of an SLI (plain old car battery). The major difference is the voltage point when fully discharged."
I have to disgree with you most strongly, Alan. Every lead battery maker disagrees with you as well. Deep cycling an SLI (car) battery as little as 5-6 times can ruin it. They are designed to supply a kilowatt or two for about three seconds to start the car, but never to be cycled to any appreciable depth, not even to 10-20% of capacity.
OTOH deep cycle batteries are designed to be routinely cycled to 50% depth 300-500 times (depending on makers claims) and usually 5-100x to full depth.
A large SLI battery (group34 or group 78) might be rated at 50AH capacity, although you'll see many of them do not even show an "AH" capacity anymore, they only show "cranking" CA and CCA ratings or RA "reserve amps" ratings, to indicate they are simply not suitable for deep cycling. Take one down to 50% capacity by pulling 20-25AH out of it...and you might get away with that 20 or even 50x before there are permanent losses in capacity. Compared to 500x for a true deep cycle?! I call that a significant difference in the charge life cycle. The harder you pull 'em down, the faster that difference will show.
That's one of the few things that *all* the battery makers agree on. Keep an SLI battery on hand for deep cycling...and you may get away with only using it five times over five years. Maybe that's enough. But it isn't what a deep cycle has to offer.
My wife and I live out in the country. It has its advantages and disadvantages. When we moved here a few years ago we found out what the disadvantages were, flakey commercial power. At some point I decided enough is enough and would go with backup power. When I was trying to decide what I wanted to do with emergency power I weighed the options. I decided I didn't want to be bothered with batteries, inverters, solar panels, switches, a mess of wires and what ever else goes along with providing backup power. All I wanted to do is provide some basic power needs like keeping the oil burner going for heat during the winter, hot water 24/7, the frig to keep food and beer cold, the water pump so my wife wouldn't complain about having to use a tree and lights, essentially the basics. So what I ended up with was a backup generator integrated into the home wiring system. So I went big time and it provides me with the everything I need to run the home as if commercial power is available and I wouldn't have to listen to my wife complain and I can still watch TV and play radio if need be. The convenience was well worth the expense.
by K1CJS on March 12, 2006 Mail this to a friend!
"They...(auto starting batteries)...are designed to supply a kilowatt or two for about three seconds to start the car, but never to be cycled to any appreciable depth, not even to 10-20% of capacity."
I would have to disagree with this statement, unless you meant the batteries made in the nineteen sixties. Modern car batteries are designed to be somewhat forgiving in that respect. A quality car battery can supply power to the many accessories in modern cars for a time and still start the car afterwards with no problem.
The key point is not to discharge the battery too much---I believe 11 volts is taking the SLI battery a little too low. (Sorry Alan.) However, there is always someone who left their lights on and cannot get their car started, who finally needs a jump to get it going. After, the battery is recharging as the car is running--with no harm to the battery.
Lastly, who of us here hasn't run their mobile rigs with the car off for periods of time with no problems whatsoever? The idea to begin with is to get a quality battery with extra capacity---instead of a bare-bones Wal-Mart special!
Getting back to the writers original post, his is one of many ways to have backup power available in the shack. Instead of fumbling with different connectors and reaching in back of your rigs in the near dark, it is much better (although a little more costly) to have auto switchover mechanisms in the shack.
A UPS is one of the best methods. 12 volt auto transfer panels (made by a few different manufacturers) with 12 volt battery backup is another. No matter which method you use it is nice to have backup power when it is needed.
by AA4PB on March 12, 2006 Mail this to a friend!
by N6AJR on March 12, 2006 Mail this to a friend!
i have a 5500 generator, 2 85 watt solar panels, a couple of small panels, lots of batteries, an 80 amp 4 battery marine charger, and several small 3 stage trickle chargers , and a sla with rig runner in the shack for the occasional quick black out.
so figure out what you need for what you want to run and set it up..
Yes, KG4RUL is correct in his statement, that repeaters are vulnerable during disasters, but nontheless, there are disasters that are more localized in their affect, and the repeaters here are strung out on a line that covers almost 200 miles, and there is a good possibility that some repeaters could survive, some of them are outfitted with battery and solar panel backup. I do have the capability with my rigs for simplex operation on all bands from 160 thru to 70cm. I have beam antennas on VHF/UHF and horizontally polarized VHF (stacked HO Loops). I think many Hams don't realize that you normally do not have to run high power during emergencies. One valuable asset is an NVIS full wave loop for 80 or 40 meters. These perform very well for moderate distances. If you do not have one they are very easy and quick to set up after a disaster, needing only wire and some support for a very low,(20 feet works quite well) antenna. I use my 80 meter full wave loop on 40 also for local nets, and find at ranges of 1000 kilometers or less it usually works quite well. My loop is at 20 feet. I also have a portable 40-60 and 80 meter NVIS antenna with supports fitted into a old Marine seabag for portable operation. The supports are made from sections of PVC pipe. My Ham friends here in Australia sometimes look askance at me about my emergency capabilities. I simply explain that 5 hurricanes passed over my house in Sneads Ferry, NC in the space of about 10 years. I guess it is burned into my brain to be ready. I do remember vividly that hurricane Floyd virtually destroyed ALL communicarions infrastructure except for Ham radio. Everything was out for about two weeks. Some power and radio and cell phone services were out considerably longer. Thats the way I saw it and whatever our opinions about what modes or frequencies we think are best, we all should have some emergency capability.
by K9KJM on March 12, 2006 Mail this to a friend!
Outgas from a battery is NOT a problem unless there has been a commercial power failure and you are charging your battery up from a discharged condition.
The big "secret" to making it all work is to have a fully automatic type charger that will shut off when the battery is fully charged.
Around 38 bucks on sale) So for less than 100 bucks a great emergency power supply. Add a few LED lights and you are set for after dark.
One of our local two meter repeaters has been on such a set up for over 30 years now! Still going strong.
On the original Heathkit 10 amp automatic charger.
The battery is replaced every 6-8 years or so.
I see more and more public safety radio systems now powering radios the same way. There is no switchover time as the equipment is always running on the battery.
I use a 4KW generator to charge the battery and run my well pump, Only running the generator maybe twice a day for an hour or so.
The battery will power your radios for a long time, As mentioned, Especially if you watch your output power and dont transmit too much.
In the event of a power failure I shut down my computer and then also shut off my UPS.... The UPS will supply limited operating time for it if I need it, But I dont want to drain that battery on a regular basis.
Solar panels to help charge the battery are something that I am interested in and would like to add some day. Right now they are still kind of expensive for the power output.
by KE4XJ on March 12, 2006 Mail this to a friend!
Ever since Hurricane Ivan, I have had a 25 KW home standby Genset with automatic changover switch. Runs both my central air conditioners at once. Plenty of power left for Emcomm ops. After Hurricane Katrina we lived for five days on the 25 KW standby unit. It was like being on mains power. HIghly recommended here on the Gulf Coast in Mobile, AL.
by KE6GLW on March 12, 2006 Mail this to a friend!
When faced with a disaster, if I need to stay on the air, I don't care if I destroy a car battery or two by extracting every last joule. If the power is going to fail for only a short period, it's not really an "emergency" and it's not likely to kill a car battery. If power and communications are going to be out for days and we have to worry about getting aid to people, then having to replace a battery at the end is going to be a pretty minor consideration. Except in rural areas, the number of immobile cars available could keep you running for weeks. If you can start the cars, they double as handy battery chargers. (Harvesting power from immobile cars is in the plan for emergency operations in San Francisco Bay area if a major earthquake takes out the power & communication lines).
I do agree on the need to understand and practice simplex operations. Even with a few working repeaters, their numbers many not provide enough communication channels. And better antennas require fewer watts for contacts -- They increase the energy efficiency of one's operations.
Mark's (K5LXP) suggestion of using a UPS to maintain batteries is one I'd adopt. It allows a safe shutdown on your PC when the power fails and you can harvest the battery power for communications in a pinch.
by KE6SVX on March 13, 2006 Mail this to a friend!
I agree that we as hams do not hold regular nets on the designated simplex channels. Here in South Silicon Valley we mention the simplex frequencies but we don't have Net on the designated simplex frequencies. I will be bringing this subject matter up on the next Net night and hope to have this incorporated into our emergency preparedness activities.
We are in the process of upgrading the W6GGF/R repeater. Based upon what happen during the 2005 hurricane season we have purchased some heavy duty batteries for emergency backup. They are the Northstar NSB 125. We have 2 installed for a total of 250 amps. This should keep the repeater up for at least one week. Also we will be able to turn off all non essential power drains such as the modem. We are installing a low voltage disconnect to disconnect the battery when the battery voltage decreases to 10.2 volts. A West Mountain Powergate 40s was also purchased to maintain the proper battery maintenace when the battery is in standby mode. There is nothing like having an emergency and the battery fails.
Another added feature is the ability to have the Tues night Net operate on battery for 30 minutes. This is also being implemented because the batteries are only exercised during a power outages which goes in spurts. At ~1925 the controller will disconnect DC power to the Powergate which will force the repeater on to battery operation. At ~1955 the controller will switch the DC power power supply back on.
by K2GW on March 13, 2006 Mail this to a friend!
Great discussion on Emergency Power for your shack. Check out the new ARRL Emergency Power book for more ideas. My home station has a 75 amp hour Gel cell floating across my Astron RS-35 power supply through a RigRunner per my article in the October 2004 QST. I also have a UPS for my computer, but the simple addition of a large gel cell to your 12 volt bus will give you a simpler and longer lasting on air capability.
One additional thing. For most emergency Public service work, we need most hams operating from shelters, hospitals, EOC's, etc. and not working from their home shacks. So a higher priority would be to make sure that your "Go Kit" with portable batteries, power supply, extension cords and feed lines, two meter mobile rig and portable antennas and mast is also ready.
by K8MHZ on March 13, 2006 Mail this to a friend!
I have two car batteries that run my shack. They are old, used batteries. They have been run dead many times. I have boiled the electolyte out of them experimenting with charging systems.
I just fill 'em up, clean 'em off and use a regulated power supply to keep them at 13.5 volts. I have never overcharged the batteries with the power supply. I HAVE overcharged them with a 2 amp 'trickle' charger.
I have DC flourescents that are so noisy they are only used to get the other lights on.
I live near a small television station. ALL his equipment is backed up with commercial UPS units connected to dozens and dozens of car batteries. The guy that engineered this concoction told me that (despite my training to the contrary) the UPS units have no problem re-charging the extra batteries and he has no issues with gas or acid. I have to admit, all the batteries were clean and there was no sign of acid corrosion anywhere.
I keep my batteries in plastic battery boxes, available at Wal-Mart for 7 bucks or so. I have found that topping off the electrolyte and holding a 13.5 volt charge for several days seems to restore the batteries. They were cheap enough, the 'pulls' from my vehicles. They were old enough not to be trusted through the cold Michigan winters but would still start a vehicle. You can get used 'pulls' from local repair shops or junkyards real cheap or even free.
What is nice about the UPS approach and the battery w/ PS in parallel is the seamless transfer between having mains power and not having it.
Most people don't realize that you can charge your batteries with your vehicle through a 100 foot extension cord, either. This allows for the car to stay in the drive and the batteries to stay in service. Of the 90 amps or so available at the alternator, 5 or 10 will still make the trip and be plenty for a recharge. If you have a good cord with heavy wire expect 25 amps, enough to stay on the air as long as the car runs and then some. The myth is that 12 volt DC would suffer too much loss for such an application. The truth is the extra resistance slows down the procedure but does not prevent it.
I currently do not have my tube rig backed up. It can hit 500 watts at full throttle and I have not played with an inverter connected to the 12 VDC system. I also have no experience with an inverter used to create a UPS. (Do they like to be on 24/7 ?) I have a 100 watt HF that runs on the 12 V system.
I would also like to remind everyone to make sure they disconnect the main breaker to the home's service before a generator is connected to the home's electrical system. Not doing so can back feed a transformer and create thousands of volt on an outside line thought to be dead.
by N7BUI on March 13, 2006 Mail this to a friend!
Good advice Mark and I agree on your advise on the battery bank. I have built up about a 2000 watt solar panel system built from odds and ends purchased as "deals" came up over the years. All three solar panel racks track the sun and are using old C band satellite dish mounts. My battery bank consists of about 20 "new" deep cycle 6 volt golf cart batteries and about 60 used batteries of various ages. Most are deep cycle and are a couple of years old on average when purchased from a local battery store as trade-in's. My only requirement is that all the batteries be wet cells. Every three to six months all the batteries have connections cleaned, load tested, and then I use a large 200 amp charger to put an equalizer charge on the bank. Works great and in six years I have had very few battery failures. This system runs year round here in Oregon and we have about 60 percent of our electrical supplied by it. Including the ham shack. I've read all the info about mixing battery types and I suppose if I had thousands invested in my bank, I might pay more attention to it. But in my experience if the battery can supply 50 amps to a small load for 30 seconds, its worth putting into the bank until it can't pass this very simple test. Sure it won't start a car, but it certainly still has some life that can add to the total capacity of the bank.
by WA1RNE on March 13, 2006 Mail this to a friend!
There are some significant safety issues involved using automotive batteries in the way you describe and I felt compelled to write a reply, both for the sake of others and your own safety.
Some of the recommendations you are making could result in serious injury and or damaged equipment.
"I have two car batteries that run my shack. They are old, used batteries. They have been run dead many times. I have boiled the electrolyte out of them experimenting with charging systems."
"I just fill 'em up, clean 'em off and use a regulated power supply to keep them at 13.5 volts. I have never overcharged the batteries with the power supply. I HAVE overcharged them with a 2 amp 'trickle' charger."
>>> Running batteries with low electrolyte levels accelerates corrosion inside the battery, increases sulfating and reduces the battery life.
More importantly, it creates high levels of hydrogen out-gassing - which can result in an explosion. All you need is a spark, be it from a corroded or defective internal termination or an external one, like a loose terminal connection in close proximity to the battery. This is how the majority of battery explosions occur, especially in warm climates. High ambient heat and loss of electrolyte are a vicious circle that kills a battery, sometimes in a catastrophic manor.
>>Using an uncontrolled charging source will usually result in decreased battery life. It's also dangerous in that depending on the given charging source, including its internal source impedance, cable drops, etc. will determine how much overcharging occurs, which can also boil off electrolyte and cause all the safety issues mentioned above.
"I live near a small television station. ALL his equipment is backed up with commercial UPS units connected to dozens and dozens of car batteries. The guy that engineered this concoction told me that (despite my training to the contrary) the UPS units have no problem re-charging the extra batteries and he has no issues with gas or acid. I have to admit, all the batteries were clean and there was no sign of acid corrosion anywhere."
>>> The TV station engineer must be using a UPS that includes a commercial charging system to properly maintain such a bank of batteries. It is also highly unlikely the batteries are automotive SLI types.
Another example is Electric Power Substations. They use banks of deep cycle batteries configured to provide 48, 125 or 250 vdc to run their protection system, i.e. protective relays. The charging systems are significantly sized commercial units that maintain the batteries at the correct voltage and charge them at the correct current and intervals. Flooded types (like most non-maintenance free types require continued watering to ensure electrolyte levels stay within specifications. Some even use automatic watering systems!
"I keep my batteries in plastic battery boxes, available at Wal-Mart for 7 bucks or so. I have found that topping off the electrolyte and holding a 13.5 volt charge for several days seems to restore the batteries. They were cheap enough, the 'pulls' from my vehicles. They were old enough not to be trusted through the cold Michigan winters but would still start a vehicle. You can get used 'pulls' from local repair shops or junkyards real cheap or even free.
What is nice about the UPS approach and the battery w/ PS in parallel is the seamless transfer between having mains power and not having it."
"Most people don't realize that you can charge your batteries with your vehicle through a 100 foot extension cord, either. This allows for the car to stay in the drive and the batteries to stay in service. Of the 90 amps or so available at the alternator, 5 or 10 will still make the trip and be plenty for a recharge. If you have a good cord with heavy wire expect 25 amps, enough to stay on the air as long as the car runs and then some. The myth is that 12 volt DC would suffer too much loss for such an application. The truth is the extra resistance slows down the procedure but does not prevent it."
>>> The best thing this scheme has going for it is the 100 foot long cable – an inadvertent means of current limiting that is dependent on wire size and cable length. A 100 foot long run of #14 extension cord has approximately 0.5 ohm of resistance (0.0025 ohms/foot, 200 feet round trip); with a nominal alternator output of say 14.4 volts, you will be lucky to have 2.4 amperes available to get the battery charged to a nominal 13.2 volts. Over several hours, this probably wouldn't damage the battery but it would take quite a while to charge it.
Running batteries of different capacities in parallel is not a good idea because the charging requirements between the vehicle battery and the "shack' battery are likely to be considerably different.
Again, my concern is about your safety and that of others; no disrespect intended.
by KU4YM on March 13, 2006 Mail this to a friend!
Since modern radios are EXTREMELY voltage sensitive, performance will deteriorate with the battery voltage. This problem can be elimimated, however, by including W4RRY's (see his call on QRC.COM) Battery Booster. Installed between the battery and the radio, it maintains a constant 13.8v to radio even as the battery voltage drop.
by KE6GLW on March 13, 2006 Mail this to a friend!
I have sometimes wondered about the relative run times you'll get off a battery with and without DC-DC converters/voltage maintainers like the BatteryBooster. Is the loss through the converter (10%-20%) offset by the ability to run the rigs at lower, battery-exhausting voltages? For example, with a discharge rate of C/10, lead acid batteries will put out about 11.5V when 80% discharged (Or about 10.9V with 20% of the charge remaining at a discharge rate of C/5). Depending on the discharge rate and the low-voltage tolerance of the radio, it could be a pretty close call. But it won't be good for the battery to drain like that very often (but in a pinch?...). $100 invested in lead & acid instead could ultimately yield more AmpHrs.
by N5YPJ on March 13, 2006 Mail this to a friend!
IS it feasible to connect parallel a deep cycle battery to a computer UPS to give it longer operating time. I always wonder if the inverter has a duty cycle??
by KILOWATT on March 13, 2006 Mail this to a friend!
>>"...how to operate in a simplex enviroment. That means formal net procedures and traffic relays."
That's the one reason I stay out of all of the "Emergency Radio" crap. They're usually headed-up by guys that have accomplished no more in life than getting a ham ticket and now need some affirmation of their manhood.
Before I'm flamed; I know not EVERYONE falls into this category. I'm sure there are some well-meaning hams out there that are TRULY concerned about public safety. Kudos to you if you're one of them.
We all know the ones I'm speaking of, right?
by KC8VWM on March 13, 2006 Mail this to a friend!
I have tried that experiment in the past.
It does work, however I found most computer UPS backup systems generated a great deal of RF hash in my radio equipment.
Another problem I experienced when using a computer UPS on radio equipment is that they are poorly shielded and are sometimes susceptible to RF when transmitting.
The UPS started doing strange things like "clicking" and going all intermittent for some reason even at relatively low RF power output levels.
I later decided to choose a well shielded quality built inverter that exhibited an acceptable sine wave, didn't generate RF hash and I also purchased a seperate automatic float charger to maintain the battery.
I have solar panels I use as a backup charging system however, I don't use the solar panels as the primary method of maintaining the float charge on the battery until the lights go out.
I do appreciate your safety comments.
We live in a climate where heat is not an issue. I can count the days each year where my basement gets over 80 degrees on one hand. Less than 70 is the norm.
"Maintenance Free" batteries still allow for access to the cells in most cases. It just takes a screwdriver and some effort.
The TV station I was at was NOT using commercial grade UPS's. He was using regular off the rack UPS gear for computers. He was also using regular car batteries, and none of them in a box. It was quite a sight. What I expected to see was corroded batteries and UPS boxes that failed due to the high current required to charge car batteries. I saw nothing of the sort.
Do I recommend such a thing? Certainly not. But, I think, after seeing dozens of batteries used as back up power for UPS boxes, I think we may just be safe to have a couple in a box built for the purpose protected by fuses located a few feet from the batteries.
The things I mentioned weren't necessarily suggestions. Just observations. Also, a decent 100 foot extension cord would be a # 12. Add to the fact that you can pair up the ground and the neutral on the neg side and you get a much better delivery to the battery. Most can do with 50 feet. SOW cord is nice stuff for this purpose.
Yeah, I should have added to my post "for educational purposes only"
by KC0NPF on March 13, 2006 Mail this to a friend!
good question, I've often wondered this myself. I'd imagine it depends on the UPS size to begin with. I wouldn't charge an empty deep cycle battery off of the inverter's charging circut, it'll keep loaded down to full capacity for DAYS before that battery comes back up to normal voltage. In a pinch I'd hook my UPS to a deep cycle, but if power's out, my cable modem's out, and chances are good that if i'm in an emergency where i ~need~ my computer for anything (we're talking desktop now) I'm probably not going to be able to get out to the internet.
I'd run a laptop for emergencies, some of them can even run direclty off of 12v though most don't.
by WB4M on March 13, 2006 Mail this to a friend!
You might decide to build the KC8VWM - FEMA grade portable power plant.
This is a one of a kind, emergency power source specifically designed and intended to operate any station, anywhere, anytime - during and/or after any disaster event.
Extremely rugged engineering and design. Frame body constructed from high tensile angle iron bolted together with stainless steel. No weak welding spots to rust and break. - Ever!
Go ahead, toss it over an embankment! Hit it with a truck! All wiring connections are completely encased in epoxy too! Watertight metering. Mil spec switches won't snap and break in the cold either.
Wiring is all protected and sealed inside water tight harness tubing. So go ahead and hose it down with a garden hose! Pull it up a flight of stairs, let it tumble down a flight of stairs, tow it behind your car, pull it uphill over any terrain - both ways, ...you can even dare take it to your next field day event!
Operates with or "WITHOUT" a battery source. Operates with or "WITHOUT gasoline. Operates with or "WITHOUT" a functioning alternator.
BRING IT ON! - Go ahead...!! Turn off the lights already!!
by WA2JJH on March 14, 2006 Mail this to a friend!
3)Many, many D alkaline cells in series parallel config.
There are some great Inverters that do deliver 80% eff. However locate far from you rig.
One of the BEST bargains was this yellow gizmo I purhased at a cleareance shop.
A)20A cont/80 peak for jumping starting an auto.
An Air compressor is built in. I found the air compressor great for many other uses.
Lithium/computer batts with a new 15 ninute charger is my latest prototype.
Many great strides have been made with the better high frerquency/eff. Inverters. 500W@110 true sine wave, sell for a mere $79.
I use 40A lead acid cells for the inverter. It is constantly trickle CHARGED. I use a 2A trickle charger.
Solar, wind and non endothermic biofuels also CAN BE USEFULL. non endothermic biofuels use natual yeats and micro organisms to break down plastic into a usable fuel. NO EXTERNAL POWER IS USED FOR THIS REACTION!
no you cannot fuel up your Delorian with a few plastic bottles!!!!
A solor powered refinary could convert the crude bio-fuel into a usefull gasoline substitute.
NO SIZE FITS ALL!!! ALWAYS THINK APPLICATION SPECIFIC!
by N4LI on March 14, 2006 Mail this to a friend!
2. Wait ~ 10 seconds.
3. Hear a thud, as switches are thrown automatically.
4. Hear the sound of a diesel motor starting on a 65 kw generator.
5. Lights come back on.
When City power returns, the system switches back over, and the generator shuts down in (I think) 10 minutes.
It works, but it's way too expensive for what it does. But, SHE wanted it, not me.
Oh, I also have a 80 ah gel cell and a couple of booster boxes. We're set.
by K2GW on March 14, 2006 Mail this to a friend!
>>IS it feasible to connect parallel a deep cycle battery to a computer UPS to give it longer operating time. I always wonder if the inverter has a duty cycle??
>>I have tried that experiment in the past.
>>It does work, however I found most computer UPS backup systems generated a great deal of RF hash in my radio equipment.
If you get a good commercial UPS of over 1000 Watts output you'll find the shielding, and inverter sine wave output are much better . See http://www.jkovach.net/projects/powerquality/ for scope shots of various UPS putputs.
The small ones for home use in plastic cases are much worse in this regard. You get what you pay for.
Also my commercial grade APC 1400 steel enclosed rack mount UPS actually has a large Anderson Powerpole jack on the back for connecting an external battery bank.
That said, for most Amateur Station uses, you'll get a much longer run time for a given battery size by just using the 12 volts directly, instead of converting it to 120 AC just to run a power supply to provide 12 volts again.
by WD9I on March 14, 2006 Mail this to a friend!
Did he say "Fluorescent lights in the ham shack"? Eeeeoooowwww!!!
by N9DG on March 14, 2006 Mail this to a friend!
"A tip on using computer UPS systems with generators. Many generators, especially the small "consumer grade" units, do not generate a pure sine wave at 60 Hertz to put it nicely. As a result, some UPS systems (APC and Best are what I have experience in) will balk at using the generator power."
Yupp seen this happen at last year's Field Day. I got on site and set up my gear only to find that the UPS wouldn't run on the power source that I was plugged into. As it turns out the generator being used at the FD site had a regulator failure and was putting out ~180V. The UPS said "I ain't gonna play" and refused to connect to the power source. That was actually a good thing since I suspect that the UPS might have even prevented some of my gear from getting damaged too!
"So the generator is purring along, then 15 minutes later you starting getting the low battery alarm on the UPS. You may notice the "on battery" and "off battery" flickering."
Saw this too. When FD generator #2 was brought on line its voltage was fine but it instead was out of spec for frequency. The UPS didn't like the generally 3 Hz high generator output frequency and didn't stay on line very well. Whenever one of the higher power stations was transmitting the UPS would connect to the power source because the load on the generator dropped the frequency enough so it was happy. When they unkeyed the UPS would go back on to its battery. I later checked my own generator at home and found it to be right on for both frequency and voltage so it plays nicely with the UPS.
As for batteries I just use the 12V battery from my snow plow tractor. It's a group 22 size. My theory is that any deep cycle that I would buy for emergency purposes may never get used. As such they are pricey; it also represents a lot of ongoing maintenance as well. The tractor battery is used regularly over the course of a year, so it's pretty well topped off at all times, and it is replaced every 4 years or so. I've decided that it will be plenty good enough for battery only emergency uses if I ever need it. Otherwise the generator is my primary backup power source.
by AA4PB on March 15, 2006 Mail this to a friend!
I have florescent lights in the shack. Even an AM broadcast band radio doesn't pick them up unless you hold it within about 6-inches of a light fixture. Florescents aren't the RFI generators they once were.
by WA8MEA on March 15, 2006 Mail this to a friend!
I am surprised Katrina didn't teach some of us hams a better lesson. Your battery power might keep your HT running for hours. But what if the repeaters in your area are all down? What if the power is out at your local gas station? There goes the fuel for your generators! And what about that 100 watt rig of yours? Calculate just how many MINUTES of usage you will be allowed on even the best Sears Diehard marine battery, as you try to contact the outside world to see how bad the devastation is.
I KNOW I'm going to catch wind from some folks who like microphones and amplifiers. But low power CW can do wonders in an emergency situation. Especially an emergency of long duration. You can send and receive for days on an auto battery.
Just give it some serious thought.
by KE4FES on March 15, 2006 Mail this to a friend!
Caution: USING VENTED LEAD ACID BATTERIES.
DURING THE CHARGING CYCLE THEY EMIT HYDROGEN GAS.
EXPLOSIVE! STATIC OR OTHER IGNITORS CAN RUIN YOUR DAY.
POSSIBLY DEMISE YOU & OR YOUR DWELLING. CONFIRM THE BATTERY MANUFACTURERS APPLICATION APPROVAL BEFORE INSTALLING IT. Sealed GEL CELLS DONT VENT.
Engine generators : Some "cheap" ones create lots of "static" IN their output . Confirm their specs.
quality BEFORE you buy ! Do not place close to the house, they catch on fire sometimes, takes only once.
PERMANENT INSTALLATIONS; FOLLOW THE LOCAL INSTALLATION CODES ! IF NOT YOU COULD VOID YOUR HOMES INSURANCE .
by KB9YKG on March 15, 2006 Mail this to a friend!
You can build a simple circuit with a couple of relays to automatically switch between you power supply and backup battery when the power goes out. It will also keep you deep cycle battery charged when the power is on. You can see it at http://www.andrewknepler.com/auto_backup.pdf.
by KC2MMI on March 15, 2006 Mail this to a friend!
"Calculate just how many MINUTES of usage you will be allowed on even the best Sears Diehard marine battery,"
Well, online they don't show the Diehard marine batteries but Sears does show the Group31 Optima Bluetop. Conventional Group31 batteries usually meet or exceed a 100AH rating, but Optima says "75Ah at c/20" and 155 minutes with a 26A drain running, about 2-1/2 hours of constant TX for a typical 20A rated rig. (Which will have low voltage problems before then, not to mention, can't run that long continuous tx.) More likely, 4-8 hours of intermittent calling and transmit use. Figure 10-15% more time, and power, for any flat-plate cell, AGM or wet, of the same group size.
On battery acid, hydrogen, and explosions? One of the hits on the web claims there are 6000 incidents of battery charging explosions in the US resulting in blindness or some loss of vision every year. As against nearly 400 million vehicles on the road, the largest source of battery explosions.
Just goes to show someone can get away with almost anything for a very long time...but for six thousand people per year, ignoring the charging warnings is a very expensive and permanent mistake. I know someone who had that problem in a car. He was lucky, when the bandages came off, he could see.
by WD9I on March 16, 2006 Mail this to a friend!
Would a plan to beat the other looters over to the Interstate battery store be a consideration? Their AGM batteries have some charge on them already but usually need to be topped.
by KE4ZHN on March 16, 2006 Mail this to a friend!
I use a small 4kw Coleman genny for emergency power. I also keep a couple of tractor batteries around too. Good enough for my usage. During the hurricanes I lost power for a week and the 8hp Briggs on my genny just chugged along like nobodies buisness. In a weeks time I burned about 25 gallons of fuel. I didnt run the genny 24 hours a day. I would run it for awhile and shut it down to conserve fuel. Its pretty fuel efficient for its size. It uses about 5 gallons of gas for every 16-18 hrs of operation. If gas stations are down its a simple matter to siphon some fuel from a vehicle. If things are so bad that utilities are down for more than a week or two I would think that you have much more to worry about than electricity.
by KC8VWM on March 16, 2006 Mail this to a friend!
Would a plan to beat the other looters over to the Interstate battery store be a consideration?
Everyone else in society will be looting TV sets, designer running shoes and running around with grocery carts stacked up with DVD players.
Hmmm.. Come to think of it, no one would probobly notice or even bother to care if they saw someone running around with a car battery.
by K4SHF on March 16, 2006 Mail this to a friend!
I also float batteries (some of those big SLAs) on my power supply. Only problem was once I accidentally bumped off the power switch...ran off battery for a week before I noticed....then when I turned the supply back on, it about cooked itself (Astron 20 Amp). I've just ordered a 50 amp to help resolve that problem. The Astron also needs to be modified so when the mains go out, the voltage on the output will eat the regulator chip. There is a simple mod of adding in a resistor that takes care of that.
by W8SWL on March 18, 2006 Mail this to a friend!
I have had a Wal Mart 105 amp deep cycle in the shack since the fall of 1999 ($89 then) in preparation for Y2K. It sure came in handy when we had the big multi-state power outage in August 2003. I have always had it on 1.5 amp trickle charge, but the voltage would vary. I recently obtained an Iota DLS-45 amp power supply that charges the battery and powers the station now. If the mains power fails, the battery is charged and ready to go automaticly.
Six years is a long time for this battery to die and when it does go, I'll replace it with two 115 amp Wal Mart deep-cycles that run $55 each. I'll keep them parallel to each other and double my capacity.
by K4SHF on March 21, 2006 Mail this to a friend!
I just purchased an RS-50M Astron. It says you can have batteries connected and diode CR5 protects the transistors. In the past, on smaller units, there was a mod to add a resistor between the wiper of the voltage pot and U723 (regulator IC).
Apparently this is not the case in the larger units? Anybody know from experience?
by K2GW on March 22, 2006 Mail this to a friend!
I wrote the article on modifying the Astron Linear Power supplies in the October 2004 QST based on some of the pioneering work by CAP and adding a RigRunner for the fusing. Essentially it's just limiting the current back in to the regulator chip.
I've successfully done it on RS-35's and RS-20's, but haven't opened up an RS-50 yet. So far, all of the RS series power supplies I've opened use the same regulator circuit board, so if the RS-50 does as well, it should work there too. The essential difference between them has been the size of the transformer, but regulator boards look the same.
If the circuit for your RS-50 is the same, then you should be OK.
by K4SHF on March 22, 2006 Mail this to a friend!
I took the plunge, hooked up to batteries first. Seems to be no problem. I'll keep my eyes open for smoke.
Also, I was concerned, having multiple batteries with no fusing between them or the power supply, the folks that make the "RigRunner" also make heavy duty breakers that can be used in this application.
by W8LV on March 22, 2006 Mail this to a friend!
The W8LV approach to emergency power: In an emergency, it is nice to have a small heated place with reliable 12 volt power. This allows for the use of lights and radio, and can run intermittently for hours for days with such a setup. Comfortable seating also helps to relieve fatigue during operations. Emergency refrigeration for perishables is also a good supplement--a 12Volt Coleman cooler is valuable for emergencies. Having such a power generation system that can be run directly or briefly via standby battery power is handy. Having the whole setup always at the ready to either use right at the QTH, or on the go makes this system instantly available and dependable: I simply keep both CARS gas tanks FULL and READY, and find this being in my driveway works the best.
by K4KEP on March 25, 2006 Mail this to a friend!
TIM. SCUSE THE CAPS. MUCH EASIER FOR ME TO READ AND TYPE FOR OVER 55 YEARS.
GOOD SOURCE OF BATTERIES MIGHT JUST BE IN YOUR BACK YARD. CHECK WITH LOCALS THAT MAINTAIN GOLF CARTS AND SEE IF YOU CAN SWAP FOR FOR SOME BATTERIES THAT ARE WEAK BUT NOT DEAD. I HAVE DONE THIS SEVERAL TIMES.
(CATALOG FREE BY MAIL) OR DOWNLOAD. PAGE 94/95 XANTREX PROSINE INVERTERS. 2000 WATT 4500 WATT SURGE. TRUE SIGN WAVE WITH A INTERNAL TRANSFER SWITCH. IT LOOKS TO ME LIKE THIS IS A MUCH BETTER APPROACH THAN A COMPUTER UPS SINCE IT WILL IDLE DOWN AT LOW CONSUMPTION (2 WATTS).
AND DOES NOT HAVE A LOW DUTY CYCLE MENTIONED IN PREVIOUS BLURBES. IN PROCESS OF PUTTING IN 6 T-105 TROJANS SERIES/PARALLEL WITH 4 125 WATT KYOCERA PANELS.
BY THE WAY. THEY ALSO HAVE 300 AND 600 WATT TRUE SIGN WAVE INVERTERS WITH LOW VOLTAGE CUT-OUT.
by NL7SX on April 11, 2006 Mail this to a friend!
The problem not usually mentioned is that batteries drop in voltage rapidly under load and 12 VDC operation from a battery (transceivers designed for direct battery operation) means that 13.8 vdc is never available directly from a battery. This is a recipe for audio distortion and disaster. W4RRY's booster will solve the problem and the other solution is to use cells (probably flooded)in series. For lead acid this means 7 cells in series (not 6) for full transceiver output. How does one charge a 2 Volt cell? By having it in a second 12 volt bank of cells. If you don't have 10 times the necessary battery capacity of normal 12 vdc batteries you will take the chance of low output/audio distortion, and still won't achieve the maximum power output of your rig.
by KD7LRJ on June 23, 2006 Mail this to a friend!
Plenty of people have modified small UPS units to use larger batteries for longer runtimes. I have posted some info about what I have done both for longer runtime and simply to maintain my batteries.
Nowadays you can get small UPS units (with batteries) for not a whole lot more than you can get a good battery maintainer (DON'T USE A CAR/MOTORCYCLE FLOAT CHARGER ON YOUR VRLA BATTERIES). My pages (at http://kd7lrj.blogspot.com ) show how I have modified quite a few UPSs I got for free from companies who didn't want them any more.