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--></style></head><body lang="EN-US" link="blue" vlink="purple"><div class="WordSection1"><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d">Thanks everyone for the input. Here are answers to some of the questions:</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d">I have a heat gun that runs right at 1300 watts (10.8 amps). I made before and after voltage measurements and got 6.5% voltage drop. (124 VAC versus 116 VAC).</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d">My spreadsheet predicts 3.4% VD. There are some Polaris splices that might contribute to the overall resistance.</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d">My plan would to power only the cooktop with the integrated inerter/battery/charger unit, if this becomes the decision.</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d">I like the all in one unit because I don’t want the complexity and foot-print of separate inverter and battery array. This ADU is a rental and the owners are elderly and need plug and play simplicity.</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d">We could bump the circuit to 240 VAC, or higher, for that matter. However there is an off-grid home in the middle of this feeder that taps off 120 VAC very occasionally to get through cloudy/low hydro days. Then we would need three transformers.</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d">I did recall that there are induction cooktops with batteries built in . I need to research that more thoroughly.</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d">Still pondering.</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d">William</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d"> </span></p><div><p class="MsoNormal"><span style="color:#1f497d">William Miller</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif";color:#1f497d">Miller Solar</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif";color:#1f497d"><a href="http://www.millersolar.com/"><span style="color:blue">www.millersolar.com</span></a></span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif";color:#1f497d">CA License C-10 77398</span></p></div><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif";color:#1f497d"> </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 [mailto:<a href="mailto:re-wrenches-bounces@lists.re-wrenches.org">re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>Ray Walters via RE-wrenches<br><b>Sent:</b> Saturday, March 21, 2026 6:20 PM<br><b>To:</b> <a href="mailto:re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a><br><b>Cc:</b> Ray Walters<br><b>Subject:</b> Re: [RE-wrenches] Portable power station for surge loads</span></p></div></div><p class="MsoNormal"> </p><p>I remember doing some measurements on a long wire run, and being surprised that the actual voltage drop was much less than the calculations. That's when I found a small note at the bottom of the NEC Table 8 conductor properties used for official VD calculations. The resistance is listed at 167 F (75C), so if you use the adjustment equation in Note 2, it is much less VD, and corresponds to reality. For underground conductors, I might use 25C. Use common sense. </p><p>The formula is R2=R1 (1+ a(T2-75))</p><p>I made a spread sheet about 15 years ago, that uses that formula for doing wire sizing. Happy to share, if anyone is interested.</p><p>Ray Walters<br>Remote Solar</p><div><p class="MsoNormal">On 3/21/2026 3:21 PM, Jay via RE-wrenches wrote:</p></div><blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"><div><p class="MsoNormal">Are you trying to run the whole house or just the burner? </p></div><div><p class="MsoNormal">I’m also curious about how you calculated the VD. I ran it on a few programs and it came up much less VD. I’d go direct or try the load and measure the VD. It won’t use the full power for long. Or at least when I use my induction top it takes so short to bring anything to a boil, after that it’s turned down. </p></div><div><p class="MsoNormal">Lots of options. </p></div><div><p class="MsoNormal"><br><br></p><p class="MsoNormal" style="margin-bottom:12.0pt">On Mar 20, 2026, at 11:23 PM, William Miller via RE-wrenches <a href="mailto:re-wrenches@lists.re-wrenches.org"><re-wrenches@lists.re-wrenches.org></a> wrote:</p></div><blockquote style="margin-top:5.0pt;margin-bottom:5.0pt"><div><p class="MsoNormal"> <span style="font-size:12.0pt;font-family:"Times New Roman","serif""></span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif"">Friends:</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif"">A long-time client has an ADU 755 conduit feet from the main house. They started off-grid but they are now grid connected.</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif"">In 1999 we pulled a 120 volt feeder of #1 aluminum to the ADU. This provides about 10 amps at 5% voltage drop.</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif"">This client wants to abandon a propane cook-top in the ADU in favor of an induction cook-top (indoor air pollution as a consideration). A sample two burner induction cook-top is 1800 watts--too much power draw for this feeder. </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif"">I was wondering if a portable power station rated at enough power to run the induction cook-top might solve this problem. The 10 amp power feed can charge the power station at (hopefully) an acceptable amperage over an extended time period and the power station can provide enough surge power to run the cook-top intermittently.</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif"">I see the Bluetti AC500, for example, can be adjusted to draw no more than 10 amps when plugged into AC. Unfortunately this charge rate, when running at the full 10 amps, allows little overhead for other loads. I presume this 10 amps draw is only 10 amps when the internal battery is fully discharged. Maybe other units can charge at a lower rate.</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif"">Have any of you tried this? Any input is appreciated.</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif""> </span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif"">William</span></p><p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Arial","sans-serif""> </span></p><p class="MsoNormal">William Miller</p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">Miller Solar</span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif""><a href="http://www.millersolar.com/">www.millersolar.com</a></span></p><p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">CA License C-10 77398</span></p><p class="MsoNormal"> </p><p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:12.0pt;font-family:"Times New Roman","serif"">_______________________________________________<br>List sponsored by Redwood Alliance<br><br>Pay optional member dues here: <a href="http://re-wrenches.org">http://re-wrenches.org</a><br><br>List Address: <a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a><br><br>Change listserver email address & 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>There are two list archives for searching. 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