<div dir="ltr">There is a company called Genasun that I believe makes a boost solar charge controller to do this. They are in the marine world and I haven't poured over their specs but they are worth checking out. <div><br></div><div>Try looking at </div><h1 class="gmail-product_title entry-title" style="border:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-weight:normal;font-stretch:normal;line-height:1.4em;font-family:Ubuntu,sans-serif;margin:0px;outline:0px;padding:0px;vertical-align:baseline;color:rgb(27,30,31);letter-spacing:-1px;clear:none"><font size="2">Genasun GVB-8-Li</font></h1><div><div>Good Luck!</div><div><br></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Apr 12, 2021 at 11:43 AM Jason Szumlanski <<a href="mailto:jason@floridasolardesigngroup.com">jason@floridasolardesigngroup.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"></div><div dir="auto"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">I want to charge a 51.2V LiPO battery with a single 420W 72-cell module. Vmp is 40.14V. </div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">It's one of those situations where I just need a lot of battery capacity as a backup for a specified time period, but it doesn't matter how long it takes to charge it back up. And I have space for exactly one 72-cell module.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">It's going to be a Victron inverter. I'm not sure if they make a DC-DC solution for this charging scenario or if there is another way to accomplish it without too much cost and complexity. I was half-heartedly thinking about an AC coupled microinverter, but that has drawbacks in terms of efficiency I think. Maybe that's not any worse than DC-DC conversion - I'm not sure. AC Coupling would probably be cheaper and easier. Monitoring might be difficult/limited. And AC coupling would require that the inverter be on (inverting) which isn't ideal for this situation either.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Thanks in advance,</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br></div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Jason Szumlanski</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Florida Solar Design Group</div></div>
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</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr" class="gmail_signature"><div><br></div><div><font color="#305A78" face="'times new roman', serif"><br></font></div><div><br></div>Mac Lewis<br><br><span style="font-family:"Times New Roman";font-size:medium;color:rgb(255,153,0)"><b><font face="Arial, Helvetica, sans-serif" size="3"><p align="left"><font color="#000000" face="Verdana, Arial, Helvetica, sans-serif"><span style="font-size:small"><span style="font-family:arial;font-weight:normal;color:rgb(48,90,120)"><font face="'times new roman', serif">"Yo solo sé que no sé nada." </font><span style="font-weight:700;color:rgb(104,104,104)"><font face="'times new roman', serif">-Sócrates</font></span></span></span></font></p></font></b></span></div>