<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">
HI Allan,<div><br></div><div>so right you are.</div><div><br></div><div>Thanks about the surrette link. </div><div>There batteries sure seem to be prone to odd things in the PV world.</div><div><br></div><div><br></div><div>peace,</div><div><br></div><div>jay<br><div><div>On Aug 3, 2008, at 5:12 PM, Allan Sindelar wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">Jay,</font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">You're right about leaving off the post at the bottom - whoops. It's at the bottom here.</font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">About voltage drop: I meant only that by running the array at a higher voltage than the batteries, there could never be sufficient hot-weather and undersized-wire voltage drop to prevent the array from exceeding the EQ voltage of the batteries. This is most often a potential problem with 12V systems. I mentioned it only to eliminate it as a possible cause of this situation.</font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">The Surrette Tech Bulletin 614 is available for download at <a href="http://surrette.com/files/BU-RS-614.pdf">http://surrette.com/files/BU-RS-614.pdf</a>. My understanding is that this bulletin is the direct result of the complaints on this list about two years ago about Surrette battery performance and life. </font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">Allan</font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div></div> <div class="OutlookMessageHeader" lang="en-us" dir="ltr" align="left"><font face="Tahoma" size="2">-----Original Message-----<br><b>From:</b> jay peltz [<a href="mailto:jay@asis.com">mailto:jay@asis.com</a>] <br><b>Sent:</b> Sunday, August 03, 2008 1:41 PM<br><b>To:</b> Allan Sindelar<br><b>Subject:</b> Fwd: [RE-wrenches] Surrette Battery Question<br><br></font></div>HI Allan, <div><font face="Arial" color="#0000ff" size="2"></font><br></div> <div>You mention about a Surrette tech bull<span class="680222723-03082008">eti</span>n, I can't seem to find it?<span class="680222723-03082008"> </span>Can you tell me where it might be on their site?</div> <div><br></div> <div>Also I"m curious about you saying that hot modules isn't going to affect voltage drop.</div> <div>Sure it will. If the wire is upsized for the lower voltages from hot weather, then you've compensated for it, but there is still added voltage drop.</div> <div><br></div> <div>And about the adding new panels to old? I didn't see the link/post at the bottom?</div> <div><span class="680222723-03082008"> T</span>hanks,<span class="680222723-03082008"> j</span>ay<span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2"> </font></span></div> <div><span class="680222723-03082008"></span> </div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">OK, the story,</font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">This client had started off-grid in the early nineties with a tight budget. He and his wife would add modules as they could afford them, usually used. The built a homemade tracker with a Wattsun SA controller and two linear actuators, using a DPDT momentary switch to adjust elevation seasonally. Over time the tracker filled out with eight Arco 16-2000s, nine Carrizo (Arco) M52L 5V Quad-Lams, two BP 275s, and two old square whatsises with 2" cells from the seventies. </font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div><span class="680222723-03082008"></span><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">Eventually their income increased and their house and house loads got bigger. </font></span><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">They asked us to upgrade their array, which eventually led to the 8 160W modules I added on a pole-top array. There were several catches, though:</font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">1. They wanted to keep as much as possible of the original "democracy tracker" in operation;</font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">2. The house had grown over the years, and the existing tracker had to be moved 50' farther away;</font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">3. The balance-of-system was still in the original basement, now inaccessible from the outside, as the house had been expanded bit by bit in all directions. </font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">4. The #2 (or 2/0, I can't recall) USE copper array input wires had been built over and couldn't be replaced; we had to use them.</font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">We dismantled the tracker and moved the pole (yep, lifted pole, concrete and all and set it in a new, larger hole with more concrete). We put a 3R j-box where the old pole had been and trenched to the new locations. After playing with different calculations, we changed the old tracked array as follows: </font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">1. We added two BP 380s (the closest we could get then to the older 275s) and wired them as one 48V string;</font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">2. We dumped the whatsises, which had low output;</font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">3. Now I'm trying to remember: I think I wired the four 16-2000s (originally 2.2A at 12V) in parallel, then wired this set of four in series with the nine Quad-Lams (think of M52Ls, originally used in the Carrisa Plains utility central power plant in California from 1984-1989 or so, as similar to 16-2000s but with the 3 rows of cells wired in parallel, to make about 7A at 4 1/2V nominal. That's why they're called Quad-Lams: it took four in series to charge a 12V battery). </font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">So we ended up with a 17-module array wired at 48V nominal, tied in with the new 48V array. What made it so special, other than that it's the only 17-module array I ever built? When we were all done and it was charging the 24V battery through the MX60, I alternately turned each array off and let the MX60 find its MPPT voltage: the two arrays were within one volt of each other. We got it right, and I have always been especially pleased with that job.</font></span></div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2"></font></span> </div> <div><span class="680222723-03082008"><font face="Arial" color="#0000ff" size="2">That's all. </font></span></div> <div><span class="680222723-03082008"></span> </div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">_______________________________________________</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">List sponsored by Home Power magazine</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><a href="mailto:RE-wrenches@lists.re-wrenches.org">RE-wrenches@lists.re-wrenches.org</a></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><a href="http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org">http://lists.re-wrenches.org/listinfo.cgi/re-wrenches-re-wrenches.org</a></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">List rules & etiquette:</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><a href="http://www.re-wrenches.org/etiquette.htm">http://www.re-wrenches.org/etiquette.htm</a></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Check out participant bios:</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">www.members.re-wrenches.org</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div> </blockquote></div><br></div></body></html>