I just have to chime in on this one. I run my K3/100-based station on solar photovoltaic power, with a 100 AH SLA battery for storage. Quick description of this installation is that I use a charge controller to regulate battery charging. It's a Micro M+ c/c and can put out 4A for a 12VDC system. http://edge.rit.edu/content/P07308/public/Custom%20Charge%20controller The article is from October, 2001 QST.
As others have stated, you should not charge *any* battery directly from an uncontrolled source like a power supply. If you want to use the battery as the main power source and recharge it periodically (or whenever the sun shines), you have to regulate the charge rate and voltage level presented to the battery. The Micro M+ does a fine job for smaller installations, and its max charge rate of 4A is adequate for topping a battery in the 100AH class. The Micro M+ uses pulse width to control the charge rate, and this is suggested for FLA and SLA battery types - others work with this method too (AGM, etc.). You can use the Micro M+ or its equivalent for any type of source - power supply, solar PV, bicycle generator, etc. When the weather is cloudy, I use a little Tektronics 3A AC/DC power supply and just run it full bore into the c/c. This works fine too. <Details are below for those that are insomniacs> Near the _big_ PV panels on the roof are the two Siemens SR50's, which are rated 50W each, and they are in parallel for the 12VDC system. The feed to the shack travels through a weatherproof enclosure that has a 10A fuse and GFP circuit breaker. This might be overkill. Together the two Siemens 50W panels are nameplate rated at around 6A. In practice, maximum output is a little over 5A on a really good sun day. The feed down to the shack is 8AWG THHN wire, about 30 feet of it, in flexible NMT. The 8AWG is to minimize the voltage drop to the charge circuitry. Both the battery and charge controller are here in the shack. 73, matt zilmer W6NIA K3 #24, K2 #2810 On Sun, 07 Jun 2009 21:17:17 -0700 (PDT), you wrote: ><I am using an Alinco DM-330M power supply. Across the output of the <power >supply I have a 26 AH battery. If the AC power quits I have <many hours to >shut down the K3. > >Charging a battery with a DC supply not meant for that purpose is a very BAD >idea. > >In the case of Astron supplies it can damage parts of the DC regulator. If >there is a "Crow Bar" circuit that operates with a battery connected to the >power supply output it will ruin your day or even burn your house down! > >Bill - K6WLM > > > >______________________________________________________________ >Elecraft mailing list >Home: http://mailman.qth.net/mailman/listinfo/elecraft >Help: http://mailman.qth.net/mmfaq.htm >Post: mailto:[email protected] > >This list hosted by: http://www.qsl.net >Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
