<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div dir="ltr"></div><div dir="ltr">From my experience the corrosion on steel cases is from the acid/water coming out of the caps during charging. </div><div dir="ltr"><br></div><div dir="ltr">I’ve also found that caps can get clogged up over time which causes higher internal pressures which can push the liquid out further. </div><div dir="ltr"><br></div><div dir="ltr">But one thing I’ve never seen is a steel case corroded all the way through to the point of failure before the cells were dead. </div><div dir="ltr"><br></div><div dir="ltr">I don’t think gasses are the main cause of the problem </div><div dir="ltr"><br></div><div dir="ltr">Jay</div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr"><br><blockquote type="cite">On May 6, 2025, at 1:09 PM, Ray Walters via RE-wrenches <re-wrenches@lists.re-wrenches.org> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr">
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<p>Hi William;</p>
<p>Poor ventilation could be part of it, but I've also seen
corrosion problems from:<br>
clients over filling the cells, <br>
EQing to often, <br>
absorption voltage set too high and for too long, <br>
too high a charge rate, (too large an array)<br>
too high a temperature, due to floor heating and/or insulated
battery box. <br>
</p>
<p>my best systems seem to be on the lower side of array size
relative to battery size, with batteries in a basement or garage
that stays above freezing, but below 60F most of the year. <br>
</p>
<p>Sorry I don't have a line on explosion proof fans, but I have a
client with a 120 vac radon blower for the battery exhaust that
seems to do much better than the traditional DC battery fans.
(Not my install.)</p>
<p> I've only seen batteries blow twice:<br>
1) Idiot was arc welding next to a HUP battery and multiple large
sparks went right on to a cap; result: blew the top off the cell.
He had been told to construct a battery enclosure around the
batteries, but never did. <br>
2) a loose connection at a battery terminal arced, melted the lead
until the molten lead melted through the top of the case and
ignited the hydrogen, result: burned a clear flame for a few
seconds and went out without any major damage. <br>
</p>
<p>So my take away is that unless the ignition source is in the cell
or within an inch of the cap, the hydrogen is too low a
concentration to ignite. Actually, are lead acid battery internal
plates and their external connections considered "explosion
proof"? <br>
</p>
<p>Ray Walters<br>
Remote Solar<br>
</p>
<p><br>
</p>
<div class="moz-cite-prefix">On 5/6/2025 12:20 PM, William Miller
via RE-wrenches wrote:<br>
</div>
<blockquote type="cite" cite="mid:77835f3af9807be52f0c3b6d81ca8891@mail.gmail.com">
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<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Friends:</span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">I
have two flooded battery arrays that have steel cases that
are corroding. I am sure poor ventilation is the issue even
though we have passive vents high and low. I think I need
active ventilation. </span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Does
anyone have knowledge of a 120VAC explosion proof ceiling
mounted exhaust fan?</span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">Thanks
in advance.</span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif"">William</span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Verdana","sans-serif""> </span></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"">17395
Oak Road, Atascadero, CA 93422</span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">805-438-5600</span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif""><a href="http://www.millersolar.com/" moz-do-not-send="true">www.millersolar.com</a></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Arial","sans-serif"">CA
Lic. 773985</span></p>
<p class="MsoNormal"> </p>
<p class="MsoNormal"> </p>
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<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
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