A number of years ago SunPower switched to using a new cell that does NOT require positive grounding. <div><br></div><div>So there should be no problem in using that 327 as described. </div><div><br></div><div>Marco<br><br>On Saturday, January 20, 2018, Mac Lewis <<a href="mailto:maclewis1@gmail.com">maclewis1@gmail.com</a>> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi Wrenches,<div><br></div><div>I have a buddy that would like to use a leftover SunPower E20-327-C-AC, panel on his RV. Obviously he would need to take the inverter off. What I'm not sure of is if this panel can operate in an ungrounded configuration, or negative ground or does this still need a positive ground? If it does need a positive ground, are there any decent MPPT charge controllers that are fully isolated from PV to battery side, that would allow PV + ground and Battery - ground?</div><div><br></div><div>Thanks<br clear="all"><div><br></div>-- <br><div><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>
</div></div>
</blockquote></div>