battery backup, etc. for QRO K2?
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battery backup, etc. for QRO K2?
 
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I've been running a QRP K2 for about 18 months now. It has the
KBT2, and I've been powering the home station with a 10A linear PS that's adjusted to 14.2V, to keep the internal gelcell happy. Now I'm going to add a KPA100/KAT100 in an EC2 (K2 twins!) and have to upgrade my power setup. My current thinking is to use the Alinco DM-330 switching PS for space reasons (my shack shares space with my office :-) Since this will require an upgrade in my PowerPole distribution setup, and because the linear supply will go back out the bench (leaving some space on the floor), I'm thinking about battery backup, too. I know that the RigRunner folks make a couple of battery backup devices http://www.powerwerx.com/category.asp?CtgID=3580 and I have to admit that I'm tempted to buy instead of build. But I'd like to understand the tradeoffs here. I want to keep the system voltage high enough to keep the KBT2's battery happy. I suppose that I could run the system from a large battery and just trickle/float the battery from a smaller supply ... but that seems a lot more complicated (and harder to keep the voltage up for the KBT2). What have other people set up along these lines? What website should I be visiting? Is the "super" powergate really worth double the price? :-) 73 de chris K6DBG _______________________________________________ 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 backup, etc. for QRO K2?
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On Wed, 11 Jul 2007 11:22:15 -0700 (PDT), Chris Kantarjiev wrote:
>What have other people set up along these lines? What website >should I be visiting? Is the "super" powergate really worth >double the price? :-) I run my multi-receiver / multi-transceiver station from a 100 AH gel-cell float-charged by an allegedly regulated MFJ 45A switching supply through an isolation diode (one half of an automotive dual-battery isolator connected "backwards"). The steady-state load approaches 7A with all receivers and transceivers in "squelched/receive" mode. The battery bus (load) voltage is 13.4V which means that the battery is near the end of its life - it falls to 12.6V under load with the charger removed. I plan to replace it with a higher capacity battery bank by the end of the summer. I would rather set the bus voltage at the recommended 13.8 V float voltage. The only problem with this is getting the supply to maintain 14.6V. Right now it's at 14.2V and the isolator drop is the advertised 0.8V including the 0.2V drop through two shunts for measuring the battery and load currents. I hesitate to remove the isolation diode lest the supply voltage fall below the battery voltage for some reason and reverse current flows into the supply regulator. That can happen when "adjusting" the variable voltage output and it destroyed a linear supply that I had many years ago. That's how I do it. -- 73 de K2ASP - Phil Kane Elecraft K2/100 s/n 5402 _______________________________________________ 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 backup, etc. for QRO K2?
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In reply to this post by Chris Kantarjiev K6DBG
On Wed, 11 Jul 2007 11:22:15 -0700 (PDT), Chris Kantarjiev wrote:
>What have other people set up along these lines? What website >should I be visiting? Is the "super" powergate really worth >double the price? :-) I run my multi-receiver / multi-transceiver station from a 100 AH gel-cell float-charged by an allegedly regulated MFJ 45A switching supply through an isolation diode (one half of an automotive dual-battery isolator connected "backwards"). The steady-state load approaches 7A with all receivers and transceivers in "squelched/receive" mode. The battery bus (load) voltage is 13.4V which means that the battery is near the end of its life - it falls to 12.6V under load with the charger removed. I plan to replace it with a higher capacity battery bank by the end of the summer. I would rather set the bus voltage at the recommended 13.8 V float voltage. The only problem with this is getting the supply to maintain 14.6V. Right now it's at 14.2V and the isolator drop is the advertised 0.8V including the 0.2V drop through two shunts for measuring the battery and load currents. I hesitate to remove the isolation diode lest the supply voltage fall below the battery voltage for some reason and reverse current flows into the supply regulator. That can happen when "adjusting" the variable voltage output and it destroyed a linear supply that I had many years ago. That's how I do it. -- 73 de K2ASP - Phil Kane Elecraft K2/100 s/n 5402 _______________________________________________ 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 backup, etc. for QRO K2?
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In reply to this post by Chris Kantarjiev K6DBG
I think optimizing for the KBT2 is an unnecessary constraint on your new
QRO power system. The charging system for the KBT2 with the resistor is an expedient and inexpensive solution, but it isn't optimal itself. I'd recommend putting a separate connector on as Don suggests, fused directly to the battery, and then using your Battery Tender Jr to charge it up every now and then. The rest of the time, use your regular power; for example, I use a 41AH AGM and a Battery Tender (not Jr) for my K2 and 35W HFpacker amp right now. For 100W SSB, the Gamma Research HPS1a is the tiniest supply you can imagine, though reports are you need to go down to 80W for CW. It's small enough to take with you on a trip as well, which isn't something you can say about other supplies, even conventional switching supplies. (It's smaller than a KX1...) When my K3 arrives I'll be using the HPS1a at first, but eventually upgrading my 40AH AGM battery to something bigger, probably an Optima Yellow Top. I got a 5A solar panel on closeout recently and plan to use that to keep it charged during power outages, but use a Battery Tender the rest of the time. Leigh/WA5ZNU _______________________________________________ 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 backup, etc. for QRO K2?
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In reply to this post by Chris Kantarjiev K6DBG
Chris,
The way I do it with my K2 twins is to use a Smartcharger (directly connected to the battery terminals - fused of course) to power the base K2. The base K2 always runs on the internal battery. The high current supply is connected to the KPA100/KAT100 combination in the EC2 enclosure. If you find that you need to purchase a new supply just ot keep the voltage up to where the internal battery will be charged, then the Smartcharger may be a better alternative. If you want to see my implementation of the direct battery connection, go to my website http://w3fpr.qrpradio.com. 73, Don W3FPR Chris Kantarjiev wrote: > I've been running a QRP K2 for about 18 months now. It has the > KBT2, and I've been powering the home station with a 10A linear > PS that's adjusted to 14.2V, to keep the internal gelcell happy. > > Now I'm going to add a KPA100/KAT100 in an EC2 (K2 twins!) and > have to upgrade my power setup. My current thinking is to use > the Alinco DM-330 switching PS for space reasons (my shack > shares space with my office :-) _______________________________________________ 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 backup, etc. for QRO K2?
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In reply to this post by Chris Kantarjiev K6DBG
Chris et al:
A better technique is to use a power supply that is designed to float across and manage batteries. They call them RV Converters. They are very cost effective, and at least some of them are very RF quiet. No diodes are required, and the supplies are designed to withstand the loads and voltages of batteries connected across their output terminals. I recently put together such a system and made a web page with some of my experience. The one I have is rated at 60 amps and together with a 100 amp hour AGM battery powers several rigs and occasionally even a solid state amplifier requiring up to 100 amps. It has a Charge Wizard to manage the voltage profile to properly charge and maintain the battery bank, which a fixed voltage cannot do: www.hsfdg.org/wiki/DcPowerSystem -- Alan, wb6zqz >----------- Original message -------------- > > > > On Wed, 11 Jul 2007 11:22:15 -0700 (PDT), Chris Kantarjiev wrote: > > > > >What have other people set up along these lines? What website > > >should I be visiting? Is the "super" powergate really worth > > >double the price? _______________________________________________ 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 backup, etc. for QRO K2?
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In reply to this post by Chris Kantarjiev K6DBG
Thanks to all who responded - I now officially have too many options!
I didn't know about the RV converter solution; I like that idea and will keep my eye out for a reasonably priced unit for a "real" setup for my shack. I'm leaning toward getting a "normal" 30A supply in the short term, since I don't have a supply that will put out that much current, and I'm sure it will be useful in the long term. I *might* try cobbling something together with a smart charger, battery and PowerPole panel; I made up such a setup for one of my APRS installations, where the PP panel has two inputs, each fused: one for the battery, one for the charger. It would be interesting to see how well such a little charger can keep up with my (typically low duty cycle) usage pattern... (And Don, I can see that I'll be drilling a hole in my K2's case soon!) 73 de chris K6DBG _______________________________________________ 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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