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I had a very well vented automotive battery explode. The cause was
apparently an internal short. The explosion broke the case and
splattered me with acid. I was lucky and not injured. I think
the internal short rapidly vaporized the acid and the explosion was
essentially due to steam pressure. <br><br>
At 01:18 PM 12/15/2010, you wrote:<br>
<blockquote type=cite class=cite cite="">We have seen a few instances of
the batteries themselves blowing, but not from hydrogen that we could
tell. In one case a guy decided to fast charge his battery bank with a DC
welding generator...<br>
<br>
<b>From:</b> <a href="mailto:allan@positiveenergysolar.com">Allan
Sindelar</a> <br>
<b>Sent:</b> Wednesday, December 15, 2010 11:10 AM<br>
<b>To:</b>
<a href="mailto:re-wrenches@lists.re-wrenches.org">
re-wrenches@lists.re-wrenches.org</a> <br>
<b>Subject:</b> Re: [RE-wrenches] Battery based hydrogen incidents<br>
<br>
Knowledge of two incidents - sort of.<br>
About ten years ago a Hydrocap on an L16 blew apart. Not our
installation; I suspect that it became plugged up or overheated, as the
array had been recently enlarged. Explosion was contained within the
battery enclosure; just made a mess.<br><br>
About four years ago a small 12V automotive battery used only to start a
6.5 Onan generator blew up, causing modest permanent hearing damage to
the homeowner. I wasn't there, and heard about it from her. This wasn't a
venting issue, as the battery was on the floor in a ventilated room, but
rather apparently a plugged cap in the battery itself. <br><br>
Otherwise, nothing.<br>
Allan<br><br>
<b>Allan Sindelar</b><br>
<a href="mailto:Allan@positiveenergysolar.com">
Allan@positiveenergysolar.com</a><br>
NABCEP Certified Photovoltaic Installer<br>
EE98J Journeyman Electrician<br>
<b>Positive Energy, Inc.</b><br>
3201 Calle Marie<br>
Santa Fe, New Mexico 87507<br>
<b>505 424-1112</b><br>
<a href="http://www.positiveenergysolar.com/">
www.positiveenergysolar.com</a><br><br>
On 12/15/2010 10:56 AM, Exeltech wrote: <br>
<blockquote type=cite class=cite cite="">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
<a href="mailto:kent@coveoregon.com"><i>mailto:kent@coveoregon.com</a></i>
</b> wrote:<br>
<dl><br>
<dd>From: Kent Osterberg
<a href="mailto:kent@coveoregon.com">mailto:kent@coveoregon.com</a><br>
<dd>Subject: Re: [RE-wrenches] Battery based hydrogen incidents<br>
<dd>To: "RE-wrenches"
<a href="mailto:re-wrenches@lists.re-wrenches.org">
mailto:re-wrenches@lists.re-wrenches.org</a><br>
<dd>Date: Wednesday, December 15, 2010, 11:21 AM<br><br>
<dd>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>
<dd>Kent Osterberg<br>
<dd>Blue Mountain Solar<br><br>
<br><br>
<dd>Dana wrote: <br>
<blockquote type=cite class=cite cite=""><br>
<dd>Ken <br><br>
<br>
<dd>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.<br><br>
<dd> <br><br>
<dd> <br><br>
<dd>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.<br><br>
<dd> <br><br>
<dd>Q - How many battery based hydrogen incidents have happened in our
collective experience?<br><br>
<dd> <br><br>
<br>
<dd>Dana Orzel<br><br>
<dd>Great Solar Works, Inc<br><br>
<dd>E -
<a href="wlmailhtml:/mc/compose?to=dana@solarwork.com">
wlmailhtml:/mc/compose?to=dana@solarwork.com</a><br><br>
<dd>V - 970.626.5253<br><br>
<dd>F - 970.626.4140<br><br>
<dd>C - 970.209.4076<br><br>
<dd>web -
<a href="http://www.solarwork.com">www.solarwork.com</a><br><br>
<dd> <br><br>
<dd>"Responsible Technologies for Responsible People since
1988"<br><br>
<dd>Do not ever belive anything, but seriously trust through
action.<br><br>
<dd> <br><br>
<dd>From:</b>
<a href="wlmailhtml:/mc/compose?to=re-wrenches-bounces@lists.re-wrenches.org">
wlmailhtml:/mc/compose?to=re-wrenches-bounces@lists.re-wrenches.org</a>
[<a href="wlmailhtml:/mc/compose?to=re-wrenches-bounces@lists.re-wrenches.org">
wlmailhtml:/mc/compose?to=re-wrenches-bounces@lists.re-wrenches.org</a>]
On Behalf Of </b>Kent Osterberg<br>
<dd>Sent:</b> Tuesday, December 14, 2010 12:07 PM<br>
<dd>To:</b> Wrenches<br>
<dd>Subject:</b> [RE-wrenches] Battery Venting<br><br>
<dd> <br><br>
<dd>Fellow Wrenches,<br><br>
<dd>The discussion about battery venting reminds me of a useful and
inexpensive program,
<a 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>
<dd>Kent Osterberg<br>
<dd>Blue Mountain Solar<br><br>
<br>
<font face="Courier New, Courier"></font></blockquote>
</dl><br><br>
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