<div dir="auto"><div>Forgive me if I'm missing something but typically I would have sell voltage slightly higher than float and lower than absorb.. I also never use the FNDC for charge termination and instead let the charge controller do everything by voltage... this may be a slightly different logic for lifepo4 but has always worked great for me for lead acid and agms.</div><div>Best of luck!</div><div data-smartmail="gmail_signature"> </div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Fri, Sep 26, 2025, 10:52\u202fAM Dave Tedeyan via RE-wrenches <<a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>To the Outback extraordinaires,</div><div><br></div><div>I've got a dual radian, grid tied system that has been in service for about 9 years. Recently, it has started this behavior where it will stop selling to the grid on sunny days. Looking back at the data, this has happened intermittently and very infrequently a couple years ago. But now we are at the point where it happens every sunny day. Once the batteries get up to fully 100% charged (not 99%), the selling stops and the system only harvests enough solar to cover the backed up loads. </div><div><br></div><div>I got a hold of the USB card data. It appears that the inverter goes from "Sell Enabled" to "Offset" when this happens. I cannot tell whether the inverter randomly decides to switch mode and then stop selling, or whether it is the stopping selling that puts it in "Offset" mode. The sell voltage is set at 52V, and float is set to 54.4V. It looks like the batteries are generally sitting around 54V when this happens. Once the inverter enters "offset" mode, then the battery voltage stays steady at 54.0V</div><div><br></div><div>Does anyone have any idea what can be causing this to happen?</div><div>Cheers,</div><div>Dave </div><div><br></div><span class="gmail_signature_prefix">-- </span><br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><br style="color:rgb(34,34,34)"><div dir="ltr" style="color:rgb(34,34,34)"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"></div></div></div><div dir="ltr"><table cellpadding="0" cellspacing="0" style="border-spacing:0px;border-collapse:collapse;color:rgb(68,68,68);width:525px;font-size:11pt;font-family:Arial,sans-serif"><tbody><tr><td width="125" valign="top" rowspan="6" style="padding:0px 10px 0px 0px;font-size:10pt;border-right:1px solid rgb(236,189,0);width:125px;vertical-align:top"><a href="https://www.sungineersolar.com/" style="color:rgb(51,122,183);background-color:transparent" target="_blank" rel="noreferrer"><img border="0" alt="Logo" width="105" src="https://sungineersolar.com/wp-content/uploads/2019/08/Logo-Image-Only-1.png" style="border:0px;vertical-align:middle;width:105px;height:auto"></a></td><td style="padding:0px 0px 0px 10px"><table cellpadding="0" cellspacing="0" style="border-spacing:0px;border-collapse:collapse;background-color:transparent"><tbody><tr><td valign="top" style="padding:0px 0px 5px 10px;width:400px;vertical-align:top"><span style="color:rgb(236,189,0);font-size:11pt;font-weight:700">Dave Tedeyan, P.E.<br></span><span style="font-size:11pt;font-weight:700"><font color="#ecbd00">Owner | Sungineer Solar</font><br></span></td></tr><tr><td valign="top" style="padding:5px 0px 5px 10px;font-size:10pt;vertical-align:top;line-height:17px"><span style="color:rgb(236,189,0)"><span style="font-weight:700">p: </span></span><span style="font-size:10pt;color:rgb(0,0,0)">he | him | his</span><span style="color:rgb(236,189,0)"><span style="font-weight:700"><br>a: </span></span><span style="font-size:10pt;color:rgb(0,0,0)"><a href="https://www.google.com/maps/search/1653+Slaterville+Rd.+%C2%A0+%7C%C2%A0Ithaca,+NY+14850?entry=gmail&source=g">1653 Slaterville Rd.</a></span><a href="https://www.google.com/maps/search/1653+Slaterville+Rd.+%C2%A0+%7C%C2%A0Ithaca,+NY+14850?entry=gmail&source=g"> </a><span style="font-size:10pt;color:rgb(0,0,0)"><a href="https://www.google.com/maps/search/1653+Slaterville+Rd.+%C2%A0+%7C%C2%A0Ithaca,+NY+14850?entry=gmail&source=g">| Ithaca, NY 14850</a></span><br><span style="color:rgb(236,189,0)"><span style="font-weight:700">w:</span></span><a href="http://www.sungineersolar.com/" rel="noopener noreferrer" style="color:rgb(51,122,183);background-color:transparent" target="_blank"><span style="font-size:10pt;color:rgb(0,0,0)"> www.sungineersolar.com</span></a><br><span style="color:rgb(236,189,0)"><span style="font-weight:700">c:</span></span><span style="font-size:10pt;color:rgb(0,0,0)"> (607) 270-0370</span></td></tr></tbody></table></td></tr></tbody></table></div></div></div></div></div></div>
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