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--></style></head><body lang="EN-US" link="blue" vlink="purple"><div class="WordSection1"><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Mac,</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Sounds to me that “someone” (ahem…) added some sulfuric acid to the cells instead of plain distilled water.</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Either that or there is some sort of contamination in there that is raising the density or “weight” of the fluid beyond just what the proper amount of acid would do. “Specific gravity” is just a measurement of how heavy the fluid is compared to plain water (specific gravity of 1.00). Sulfuric acid is heavier than water, so when mixed will increase the density and raise the weight of the fluid. Temperature effects the measurement too of course.</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">If it turns out that acid was added, you can balance them out by removing some of the electrolyte from the high cells and replacing it with distilled water. It would be a process of trial and error to get them all the same. Remove a little, add some water, equalize again, measure S.P. and repeat as needed. </span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Leaving the electrolyte too strong will shorten the battery life, although maybe not enough to go through this ritual.</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Brian Teitelbaum</span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">AEE Solar</span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"> </span></p><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>Mac Lewis<br>
<b>Sent:</b> Tuesday, August 12, 2014 6:55 PM<br><b>To:</b> RE-wrenches<br><b>Subject:</b> [RE-wrenches] High specific gravity</span></p><p class="MsoNormal"> </p><div><p class="MsoNormal">Hello wrenches,</p><div><p class="MsoNormal">
</p></div><div><p class="MsoNormal">I just went on a service call for a new client. He had a bank of 4 year old Interstate L16HCL batteries, 2 strings of 8, 48V system, 840Ahr. We went through the batteries and got specific gravity on all of the cells post-equalization. I was a bit surprised to see some very high numbers ie over 1.32 for the specific gravities (higher than my refractometer goes). The specific gravities were all over the place, but I haven't seen numbers this high. I don't have a great explanation. He has a stacked 3648 VFX Outback system, and the set-points were 58.8V Absorb for 2 hours, and 62V Equalize for 2 hours. He has a decent amount of solar (about 3400W) and a 1000W wind generator.</p>
</div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">Any ideas why the specific gravity is so high on some cells? Also, is there anything wrong with having SG this high, post-equalization? For this very standard battery, what settings do you go with (Bulk, Absorb, Float, Eq, and times for Abs and Equalization).</p>
</div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal">Thanks in advance</p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal"><br clear="all"></p><div><p class="MsoNormal"> </p></div><p class="MsoNormal">
-- </p><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal"> </p></div><div><p class="MsoNormal"> </p></div><p class="MsoNormal" style="margin-bottom:12.0pt">Mac Lewis<b><span style="font-family:"Arial","sans-serif";color:#ff9900"></span></b></p>
<p><span style="color:#305a78">"Yo solo sé que no sé nada." </span><b><span style="color:#686868">-Sócrates</span></b><b><span style="font-family:"Arial","sans-serif";color:#ff9900"></span></b></p>
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