<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">Hello Jay,<br><br>Granted, that too can be a cause. In this instance, my friend was fastidious about battery maintenance (obsessive even). Cell caps were unobstructed. This was unquestionably an accumulation of hydrogen in one or more cells, which was then ignited by the tiniest of sparks. As I remember the situation, he called it a "learning experience", one he didn't wish to repeat.<br><br>Dan<br><br><br>--- On <b>Wed, 12/15/10, jay peltz <i><jay@asis.com></i></b> wrote:<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><br>From: jay peltz <jay@asis.com><br>Subject: Re: [RE-wrenches] Battery based hydrogen incidents<br>To: "RE-wrenches" <re-wrenches@lists.re-wrenches.org><br>Date: Wednesday, December 15, 2010, 12:04 PM<br><br><div id="yiv530796067">Hi
Dan,<div><br></div><div>I've see this as well, but I don't put it down to a enclosure problem but a build up inside a individual battery cell,( plugged cap, etc) which IMHO even if the batteries were outside wouldn't help prevent it.</div><div>Never the less, why I use eye protection every time I go see batteries.</div><div><br></div><div><br></div><div><br></div><div>Jay</div><div><br></div><div>peltz power</div><div><br></div><div><br><div><div>On Dec 15, 2010, at 9:56 AM, Exeltech wrote:</div><br class="yiv530796067Apple-interchange-newline"><blockquote type="cite"><table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font: inherit;" valign="top">38+ years in RE. Knowledge of one incident (an off-grid friend).<br><br>Very sunny day. Very windy. My friend had both PV and a wind generator (still does). He had just stepped out of the room where the batteries were located when (as he described it) he heard
something like a loud gunshot. He went back inside to find one of the L16s exploded, top completely blown off, and case broken much of the way down one side.<br><br>Had the incident occurred only minutes earlier, injuries could have resulted. He has since relocated his batteries to a dedicated (and vented) battery space.<br><br>Dan<br><br><br>--- On <b>Wed, 12/15/10, Kent Osterberg <i><<a rel="nofollow" ymailto="mailto:kent@coveoregon.com" target="_blank" href="/mc/compose?to=kent@coveoregon.com">kent@coveoregon.com</a>></i></b> wrote:<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><br>From: Kent Osterberg
<<a rel="nofollow" ymailto="mailto:kent@coveoregon.com" target="_blank" href="/mc/compose?to=kent@coveoregon.com">kent@coveoregon.com</a>><br>Subject: Re: [RE-wrenches] Battery based hydrogen incidents<br>To: "RE-wrenches" <<a rel="nofollow" ymailto="mailto:re-wrenches@lists.re-wrenches.org" target="_blank" href="/mc/compose?to=re-wrenches@lists.re-wrenches.org">re-wrenches@lists.re-wrenches.org</a>><br>Date: Wednesday, December 15, 2010, 11:21 AM<br><br><div id="yiv530796067yiv1034715313">
Sounds like, in general, that the off-grid industry has been fortunate
to not have hydrogen explosions. That's good. No explosions here
either. But one shouldn't take that as evidence that it couldn't
happen. I don't believe this is a circumstance where it is better to
be lucky than good. That's why I recommend doing the calculations.<br>
<br>
Kent Osterberg<br>
Blue Mountain Solar<br>
<br>
<br>
<br>
Dana wrote:
<blockquote type="cite">
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<div class="yiv530796067yiv1034715313WordSection1"><p class="yiv530796067yiv1034715313MsoNormal"><span style="font-size: 14pt; color: windowtext;">Ken
– </span></p><p class="yiv530796067yiv1034715313MsoNormal"><span style="font-size: 14pt; color: windowtext;"><br> </span></p><p class="yiv530796067yiv1034715313MsoNormal"><span style="font-size: 14pt; color: windowtext;">To
meet the flow have run 2 and 3 fans to meet the flow. 2” output from
the fan into a 4” header with a matching 2.5” inlet as far away on the
lowest portion of the battery box.</span></p><div><span style="font-size: 14pt; color: windowtext;"> </span><br class="yiv530796067webkit-block-placeholder"></div><div><span style="font-size: 14pt; color: windowtext;"> </span><br class="yiv530796067webkit-block-placeholder"></div><p class="yiv530796067yiv1034715313MsoNormal"><span style="font-size: 14pt; color: windowtext;">In
22+ years in off grid installations I have yet to see or even hear of
one hydrogen explosion. I get repeatedly asked why we have to go to the
efforts we go to for box and venting. I am not able to provide even one
incident that I have heard rumor of.</span></p><div><span style="font-size: 14pt; color: windowtext;"> </span><br class="yiv530796067webkit-block-placeholder"></div><p class="yiv530796067yiv1034715313MsoNormal"><span style="font-size: 14pt; color: windowtext;">Q
- How many battery based hydrogen incidents have happened in our
collective experience?</span></p><div><span style="font-size: 14pt; color: windowtext;"> </span><br class="yiv530796067webkit-block-placeholder"></div><p class="yiv530796067yiv1034715313MsoNormal"><span style="font-size: 14pt; color: windowtext;"><br></span></p>
<div><p class="yiv530796067yiv1034715313MsoNormal"><span style="color: windowtext;">Dana
Orzel</span></p><p class="yiv530796067yiv1034715313MsoNormal"><span style="color: windowtext;">Great
Solar Works, Inc</span></p><p class="yiv530796067yiv1034715313MsoNormal"><span style="color: windowtext;">E
- <a rel="nofollow" class="yiv530796067yiv1034715313moz-txt-link-abbreviated">dana@solarwork.com</a></span></p><p class="yiv530796067yiv1034715313MsoNormal"><span style="color: windowtext;">V
- 970.626.5253</span></p><p class="yiv530796067yiv1034715313MsoNormal"><span style="color: windowtext;">F
- 970.626.4140</span></p><p class="yiv530796067yiv1034715313MsoNormal"><span style="color: windowtext;">C
- 970.209.4076</span></p><p class="yiv530796067yiv1034715313MsoNormal"><span style="color: windowtext;">web
- <a rel="nofollow" class="yiv530796067yiv1034715313moz-txt-link-abbreviated" target="_blank" href="http://www.solarwork.com/">www.solarwork.com</a></span></p><div><span style="color: windowtext;"> </span><br class="yiv530796067webkit-block-placeholder"></div><p class="yiv530796067yiv1034715313MsoNormal"><span style="color: windowtext;">"Responsible
Technologies for Responsible People since 1988"</span><span style="font-size: 11pt; color: windowtext;"></span></p><p class="yiv530796067yiv1034715313MsoNormal"><span style="color: windowtext;">Do
not ever belive anything, but seriously trust through action.</span></p>
</div><div><span style="font-size: 14pt; color: windowtext;"> </span><br class="yiv530796067webkit-block-placeholder"></div>
<div>
<div style="border-style: solid none none; border-color: rgb(181, 196, 223); border-width: 1pt medium medium; padding: 3pt 0in 0in;"><p class="yiv530796067yiv1034715313MsoNormal" style="margin-left: 0.5in;"><b><span style="font-size: 10pt; color: windowtext;">From:</span></b><span style="font-size: 10pt; color: windowtext;">
<a rel="nofollow" class="yiv530796067yiv1034715313moz-txt-link-abbreviated">re-wrenches-bounces@lists.re-wrenches.org</a>
[<a rel="nofollow" class="yiv530796067yiv1034715313moz-txt-link-freetext">mailto:re-wrenches-bounces@lists.re-wrenches.org</a>] <b>On Behalf Of </b>Kent
Osterberg<br>
<b>Sent:</b> Tuesday, December 14, 2010 12:07 PM<br>
<b>To:</b> Wrenches<br>
<b>Subject:</b> [RE-wrenches] Battery Venting</span></p>
</div>
</div><div style="margin-left: 0.5in;"> <br class="yiv530796067webkit-block-placeholder"></div><p class="yiv530796067yiv1034715313MsoNormal" style="margin-left: 0.5in;">Fellow Wrenches,<br>
<br>
The discussion about battery venting reminds me of a useful and
inexpensive program, <a rel="nofollow" target="_blank" href="http://pocketengineer.design.officelive.com/battery_ventilation.aspx">BattMV</a>,
for determining ventilation requirements per EN-50272. EN-50272 is a
European standard used to determine how much air flow is needed for a
room, I don't know of a equivalent standard used in the U.S. It takes
a surprising amount of ventilation. For a 400-AH 48-volt L16 bank
charged at 57.6 volts and 24 amps, it's about 7 CFM just to keep the
%H2 down to 4%. A 12-volt Zephyr vent is good for about 5 CFM! If
you think you are venting enough, take some time and study this issue.<br>
<br>
Kent Osterberg<br>
Blue Mountain Solar</p>
</div>
<pre><hr size="4" width="90%"></pre></blockquote></div></blockquote></td></tr></tbody></table><br>
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