Battery Power
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The ongoing discussions regarding woes involving AC power supplies puzzles me, because I've operated for years from 2-volt batteries and wonder why it isn't a more common practice.
From QRP rigs to 100-watt transceivers through VHF/UHF equipment, all my equipment is powered through a single, deep-cycle RV/Marine battery in a safety housing under the bench, constantly connected to a "smart" battery charger. I took a cheap, plastic toolbox and created inside a buss arrangement with fusing to make it easy for neatly and safely connecting all the various radio power leads to one location. All of this can be done for less than $150. In practice, the 20-amp charger absorbs most of the load when a 100-watt rig is keyed and the battery simply acts like a big capacitor to stop "hash" and voltage flunctuations. When working with simple QRP rigs, the pure DC supply is a joy because it eliminates the most obvious noise source from getting into the receivers. Because the charger is quietly maintaining the battery at a trickle rate, there is little gas given off by the battery and normal household air movement is sufficient to safely eliminate any buildup. The battery box and charger sit under the operating desk, where I can keep an eye on voltages, charging rates and battery condition. I've operated this way for years without a problem, and have had batteries last seemingly forever. I replaced the last one after 10 years of use, which included some major tasks at annual Field Day events. If there are drawbacks to this type of power useage, I'm not aware of them, and highly recommend batteries as the least expensive and most stable way to feed all your 12-volt equipment. Needless to say, the isolation from wavering AC mains is a plus, along with having instantaneous emergency power when the mains fail. If there's something I'm overlooking in this type of operation anyone would like to address, I'd welcome the comments. 73, Dale K6PJV, Sacramento, CA. _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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I agree with you Dale. In my article on remote station control in October QST, I urged people to use a similar arrangement for remote operation, where a power failure can be a real hassle. In this case, I also recommend using an inverter to power things like the rotator. Larry N8LP Dale Kretzer wrote: > The ongoing discussions regarding woes involving AC power supplies puzzles me, because I've operated for years from 2-volt batteries and wonder why it isn't a more common practice. > From QRP rigs to 100-watt transceivers through VHF/UHF equipment, all my equipment is powered through a single, deep-cycle RV/Marine battery in a safety housing under the bench, constantly connected to a "smart" battery charger. I took a cheap, plastic toolbox and created inside a buss arrangement with fusing to make it easy for neatly and safely connecting all the various radio power leads to one location. All of this can be done for less than $150. > In practice, the 20-amp charger absorbs most of the load when a 100-watt rig is keyed and the battery simply acts like a big capacitor to stop "hash" and voltage flunctuations. When working with simple QRP rigs, the pure DC supply is a joy because it eliminates the most obvious noise source from getting into the receivers. Because the charger is quietly maintaining the battery at a trickle rate, there is little gas given off by the battery and normal household air movement is sufficient to safely eliminate any buildup. The battery box and charger sit under the operating desk, where I can keep an eye on voltages, charging rates and battery condition. > I've operated this way for years without a problem, and have had batteries last seemingly forever. I replaced the last one after 10 years of use, which included some major tasks at annual Field Day events. If there are drawbacks to this type of power useage, I'm not aware of them, and highly recommend batteries as the least expensive and most stable way to feed all your 12-volt equipment. Needless to say, the isolation from wavering AC mains is a plus, along with having instantaneous emergency power when the mains fail. > If there's something I'm overlooking in this type of operation anyone would like to address, I'd welcome the comments. > 73, Dale > K6PJV, Sacramento, CA. >_______________________________________________ >Elecraft mailing list >Post to: [hidden email] >You must be a subscriber to post to the list. >Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > >Help: http://mailman.qth.net/subscribers.htm >Elecraft web page: http://www.elecraft.com > > > > > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by dalekretzer
Dale Kretzer wrote:
> From QRP rigs to 100-watt > transceivers through VHF/UHF equipment, all my equipment is powered > through a single, deep-cycle RV/Marine battery in a safety housing > under the bench, constantly connected to a "smart" battery charger. I've often thought of this, although I would probably put the battery in a box outdoors, just to be 100% safe. An additional cool thing would be to supplement the AC operated charger with a solar panel. I am interested in knowing exactly what smart charger and battery you are using. I (twice!) had to clean up a PDP-11 computer room after a battery exploded as a result of a malfunction in the charger portion of a UPS. That's why I'd keep the battery outdoors. -- 73, Vic, K2VCO Fresno CA http://www.qsl.net/k2vco _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
RE: Battery Power - safety consideerations
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In reply to this post by dalekretzer
Dale,
You are correct that batteries provide a good stable source of power. Just remember that they can pack a lot of current, and they do not protect against a short circuit condition like a power supply will - if the battery terminals are shorted they can provide enough current to melt wrenches, screwdrivers, etc and spew molten metal a considerable distance. Be careful with rings, watches, other jewelery and tools around batteries. The only other thing that I can think of is that you did not mention venting the battery to outside air. Since Lead Acid batteries outgas hydrogen, it becomes an explosion hazard should it collect in sufficient quantity. Your 'under the bench location makes it even more of a problem because the air flow there is likely limited. Battery enclosures are available that vent the battery with a tube. They used to be available in RV supply centers, but I have not checked in several years. 73, Don W3FPR > -----Original Message----- > The ongoing discussions regarding woes involving AC power > supplies puzzles me, because I've operated for years from 2-volt > batteries and wonder why it isn't a more common practice. > From QRP rigs to 100-watt transceivers through VHF/UHF > equipment, all my equipment is powered through a single, > deep-cycle RV/Marine battery in a safety housing under the bench, > constantly connected to a "smart" battery charger. I took a > cheap, plastic toolbox and created inside a buss arrangement with > fusing to make it easy for neatly and safely connecting all the > various radio power leads to one location. All of this can be > done for less than $150. > In practice, the 20-amp charger absorbs most of the load when > a 100-watt rig is keyed and the battery simply acts like a big > capacitor to stop "hash" and voltage flunctuations. When working > with simple QRP rigs, the pure DC supply is a joy because it > eliminates the most obvious noise source from getting into the > receivers. Because the charger is quietly maintaining the battery > at a trickle rate, there is little gas given off by the battery > and normal household air movement is sufficient to safely > eliminate any buildup. The battery box and charger sit under the > operating desk, where I can keep an eye on voltages, charging > rates and battery condition. > I've operated this way for years without a problem, and have > had batteries last seemingly forever. I replaced the last one > after 10 years of use, which included some major tasks at annual > Field Day events. If there are drawbacks to this type of power > useage, I'm not aware of them, and highly recommend batteries as > the least expensive and most stable way to feed all your 12-volt > equipment. Needless to say, the isolation from wavering AC mains > is a plus, along with having instantaneous emergency power when > the mains fail. > If there's something I'm overlooking in this type of > operation anyone would like to address, I'd welcome the comments. > 73, Dale > K6PJV, Sacramento, CA. > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.375 / Virus Database: 267.14.21/236 - Release Date: 1/20/2006 > > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by dalekretzer
Dale, K6PJV wrote:
The ongoing discussions regarding woes involving AC power supplies puzzles me, because I've operated for years from 2-volt batteries and wonder why it isn't a more common practice....If there's something I'm overlooking in this type of operation anyone would like to address, I'd welcome the comments. ------------------------ Hi Dale - If you're talking about conventional lead-acid batteries, there is the issue of sulfuric acid, highly-flammable hydrogen gas that must be ventilated properly, and lots and lots of toxic lead when the battery is finally scrapped. Shoot, they didn't even allow those things 'indoors' on ships! They were in their own ventilated locker outside the radio room. A lot of people today are operating from living rooms, bedrooms and other places in homes where a lead-acid battery is less than welcome. That's what has made gel-cells popular, but they have severe limitations of their own compared to a normal lead-acid battery. Besides, a decent linear supply will provide decades of reliable service and not produce any RFI and last at least as long as most lead-acid batteries. The problems have started to arise with the popularity of "switching power supplies" that are light, small, and which, by their very nature, produce a lot of radio frequency interference. The better ones intended for use near radio equipment are shielded and filtered, but the RFI is always there to some degree or another. It's all a matter of what fits the need. For a growing number of Hams the need is for a small, lightweight, non-toxic power source that is a safe and convenient for use inside the living area of a house. For operators like you with a suitable shop space, a heavy-duty lead-acid battery can be a wonderful alternative that is also independent of the power lines. Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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>> Shoot, they didn't even allow those things 'indoors' on ships! They were in their own ventilated locker outside the radio room. They do allow them and need them on submarines and these batteries are big enough you could get in the jar! Only time they are vented outside is when performing an "equalizing charge." However, they do ventilate the area to prevent H2 buildup in pockets. Get out your chemistry book and work out the molar equations, for the average auto/boat deep cycle battery the amount of hydrogen released during a normal charge is minimal. Very high charge rates (60 120 amp/hr) releases H2 quicker. But there is still a limited amount. Additionally, there would be no H2SO4 or H2O left. Even if all of it was used up you are only talking a few grams (Liters) of Hydrogen and that would be released over several hours. Rich -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 267.14.21/236 - Release Date: 1/20/2006 _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Rich Lentz wrote:
> work out the molar equations How did this thread morph into dentistry? Fred K6DGW Auburn CA CM98lw _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Rich Lentz
Rich wrote:
They do allow them and need them on submarines and these batteries are big enough you could get in the jar! Only time they are vented outside is when performing an "equalizing charge." However, they do ventilate the area to prevent H2 buildup in pockets. ----------------------------------- Yes. It's a little hard to get fresh outside air into a sub most of the time <G>. And in the old diesel subs the batteries were darn near as dangerous as the enemy in wartime, but that was a special case not likely found at home; The mixture of the electrolyte and sea water produced deadly chlorine gas. I would consider the most dangerous problem today the sulfuric acid. Working on marine systems, I was terribly, terribly careful when checking batteries to avoid splashing any electrolyte. Still I didn't own a single pair of work pants that didn't have holes from very, very tiny electrolyte droplets. Of course, after the acid has a little while to work, the hole isn't nearly as tiny as the droplet was. There may not be a huge amount of hydrogen released, but you don't need a lot. There's a reason why one should never attach a live circuit directly to a lead-acid battery, such as when jump-starting a car. The last connection is ground and it goes to a point away from the battery because that inevitable spark when the clamp makes contact has caused entire batteries to blow up, piercing the hapless individual with lead shrapnel from what were the plates while simultaneously bathing him (or her) in sulfuric acid and causing serious burns from the flames. >From what I read, the modern "maintenance free" car batteries are no exception. They have exploded when left alone! As one survivor reported, "If you have to be near an exploding battery, be two floors down, in an office, in another building. Worked for me." For the full story see: http://www.rayvaughan.com/battery_safety.htm Ron AC7AC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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