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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Thanks Dan/Dick and Larry – <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>My concern was too high a charge rate, particularly when the batteries are cycled during or after an outage when the controllers are delivering maximum current and the inverter is not selling, yet not wanting to limit the charge controllers when we’re back in grid tied mode. Outback noted that you can just limit the controllers during extended outages, but I would prefer that customers not have to make adjustments to the charge rates.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>What I failed to consider is the particularly high charge rates that AGMs are able to withstand compared to FLAs. With a few tweaks to the system design we can easily hit a ~ .25C rate which is ideal for the batteries.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I like the perspective of the inverter as diversion controller when it’s in sell mode. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Thanks again for your help!<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Rich<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> re-wrenches-bounces@lists.re-wrenches.org [mailto:re-wrenches-bounces@lists.re-wrenches.org] <b>On Behalf Of </b>dan@foxfire-energy.com<br><b>Sent:</b> Sunday, September 02, 2012 11:01 AM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> Re: [RE-wrenches] Grid tie with BB<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:black'>I'm with Dick. I liken grid tied inverters to diversion controllers. MPPT charge controllers (In Grid Tie Mode / talking to a HUB), pretty much just track a max power from the array. Good luck.<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:black'>db<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:black'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:black'><br>Dan Brown<br>Foxfire Energy Corp.<br>Renewable Energy Systems<br>(802)-483-2564<br><a href="http://www.Foxfire-Energy.com">www.Foxfire-Energy.com</a><br>NABCEP #092907-44<o:p></o:p></span></p></div><div><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:black'><o:p> </o:p></span></p></div><blockquote style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 6.0pt;margin-left:6.0pt;margin-top:5.0pt;margin-bottom:5.0pt' id=replyBlockquote><div id=wmQuoteWrapper><p class=MsoNormal style='margin-bottom:12.0pt'><span style='font-size:10.0pt;font-family:"Verdana","sans-serif";color:black'>-------- Original Message --------<br>Subject: Re: [RE-wrenches] Grid tie with BB<br>From: <a href="mailto:Richard.L.Ratico@VALLEY.NET">Richard.L.Ratico@VALLEY.NET</a> (Richard L Ratico)<br>Date: Sun, September 02, 2012 9:16 am<br>To: <a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a><br><br>Rich,<br><br>If I understand your question, I think you're missing the functioning of the<br>inverter. Working independently of the charge controller, it will sell to<br>prevent overcharging the batteries. Correctly configuring the inverter's voltage<br>thresholds accomplishes this.<br><br>Dick Ratico<br><br><br>--- You wrote:<br>Wrenches,<br><br>I'm have a mental block with battery backup systems such as the Outback<br>Radian. Perhaps someone can help me get over it!<br><br>Essentially these systems sell back power off the top of the battery bank<br>and the array is maintaining the state of charge of the battery bank through<br>traditional charge controllers. If you have a modest battery bank sized for<br>limited use on critical circuits and a good size array for the benefit of<br>net metering I would think it would be necessary to limit the current the<br>charge controllers are capable of delivering to the battery bank to prevent<br>damage to the batteries when the controllers are Bulking or Absorbing, but<br>then it would seem that we limiting the utility of the larger array. If the<br>current from the controllers was not limited they will self-limit as voltage<br>rises, plus I suppose they will mostly be in float mode except when the<br>batteries are cycled but again it seems that we are limiting the capability<br>of the array compared to a straight grid tied system with a traditional grid<br>tied only inverter.<br><br>An example would be a 8000 watt array using a couple of flexmax80<br>controllers with a string of 8 - L16 AGMs feeding a Radian.<br><br>What am I missing here?<br><br>Thanks <br><br>Rich<br>--- end of quote ---<br>_______________________________________________<br>List sponsored by Home Power magazine<br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><br><br>Options & settings:<br><a href="http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org</a><br><br>List-Archive: <a href="http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org</a><br><br>List rules & etiquette:<br><a href="http://www.re-wrenches.org/etiquette.htm">www.re-wrenches.org/etiquette.htm</a><br><br>Check out participant bios:<br><a href="http://www.members.re-wrenches.org">www.members.re-wrenches.org</a><o:p></o:p></span></p></div></blockquote></div></body></html>