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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Following is an entry from a Backwoods Solar email that I received today. I would like to share this as a teachable point for RE techs not familiar enough with proper battery bank care and as a reminder for those of us with years of storage battery experience. <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>I have underlined the two issues in the Backwoods email copied below my bullet points to highlight the teachable issues.<o:p></o:p></span></p><p class=MsoListParagraph style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:12.0pt;font-family:Symbol'><span style='mso-list:Ignore'>·<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Checking wiring connections: Check not only for tightness but also for temperature. There are two simple methods that work well: #1) Use an IR Thermometer to ensure all connections are of a similar moderate temperature. #2) Use your fingers to check temperatures. I'm practiced at this second method because inexpensive IR thermometers were not available when I began to care for storage batteries. I simply use my bare fingers (with a light coating of petroleum jelly) to wiggle test each battery cable at the battery terminal. Fingers are sensitive enough to gauge proper temperature. I have easily found several warm or hot connection points over the years caused by loose or corroded hardware. Do this as preventive maintenance every time you water the batteries or bi-monthly with sealed cells. Corrective measures (tightening, or taking apart and cleaning, or replacing, and reinstalling) are taken immediately when a warmer than usual connection is identified.<o:p></o:p></span></p><p class=MsoListParagraph style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='font-size:12.0pt;font-family:Symbol'><span style='mso-list:Ignore'>·<span style='font:7.0pt "Times New Roman"'> </span></span></span><![endif]><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>It is not recommended by most veteran wrenches to use any "anti-corrosion paste" on the terminal connections. This has been discussed a few times over the years on the Wrenches list. Most of us have found that a thin coating of petroleum jelly (Vaseline is one brand) does the best job of protecting against corrosion while still allowing some visual inspection.<o:p></o:p></span></p><p>from Backwoods Solar 1/20/17. << This past summer Backwoods had a visit from one of our retired co-workers, xxxxx. While it is always good to have friends visit, the circumstances for his dropping by were less than ideal.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>A small, catastrophic failure had led to the loss of a battery bank, two inverters, and a voltage converter. Ultimately, the failure was traced back to a single nut and bolt in the battery bank cable connections, that had developed hidden corrosion over time. Corrosion causes resistance to the flow of electricity, which in turn generates heat. With enough corrosion, and enough current flow, the amount of heat generated can be sufficient to melt battery terminal connections; which is exactly what happened in xxxxx’s case. The melted metal flowed between the negative and positive terminals of his industrial battery, causing a high power short that was beyond the capabilities of any of the circuit protection, resulting in the damage to the equipment.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Now keep in mind, xxxxx is one of the more detail-oriented people we’ve had here at Backwoods. The discipline of a military background, along with critical thinking of an engineer, were still not enough to overlook one very tiny detail. xxxxx does his mechanical maintenance on a routine schedule; <u>checking for tightness in wiring connections</u>, cleaning accumulated spray off battery tops, cleaning out dust and spider webs, <u>and keeping his battery terminal posts coated with anti-corrosion paste.</u> This is not the type of person you’d expect to see such a failure.</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>So what happened? It all boiled down to the battery terminal connections. What xxxxx had NOT done, was dissembled the nut and bolts from the battery terminals and cables to check for internal, hidden corrosion. It had been about 6 years since he had done that level of inspection. When previously reviewed, the hardware had been thoroughly inspected, cleaned, and re-assembled, and then coated with <u>anti-corrosion paste on the exterior</u>. In one of the 16 nut/bolt pairs, a small bit of contamination or moisture must have been left trapped inside. Over the course of the next six years, the corrosion grew, contaminating the entire connection; but was NOT visible externally at all! >><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Best regards,<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'>Dave<o:p></o:p></span></p><p class=MsoNormal>David Palumbo <o:p></o:p></p><p class=MsoNormal>Independent Power LLC<o:p></o:p></p><p class=MsoNormal>462 Solar Way Drive<o:p></o:p></p><p class=MsoNormal>Hyde Park, VT 05655<o:p></o:p></p><p class=MsoNormal>802-371-8678 cell<o:p></o:p></p><p class=MsoNormal>802-888-4917 home<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>