<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:"Century Gothic";
panose-1:2 11 5 2 2 2 2 2 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";
color:black;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:"Century Gothic","sans-serif";
color:windowtext;
font-weight:normal;
font-style:normal;
text-decoration:none none;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext'>Ken – <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";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.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";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.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext'>Q - How many battery based hydrogen incidents have happened in our collective experience?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext'><o:p> </o:p></span></p><div><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:windowtext'>Dana Orzel<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:windowtext'>Great Solar Works, Inc<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:windowtext'>E - dana@solarwork.com<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:windowtext'>V - 970.626.5253<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:windowtext'>F - 970.626.4140<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:windowtext'>C - 970.209.4076<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:windowtext'>web - www.solarwork.com<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:windowtext'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:windowtext'>"Responsible Technologies for Responsible People since 1988"</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:windowtext'><o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Century Gothic","sans-serif";color:windowtext'>Do not ever belive anything, but seriously trust through action.<o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:14.0pt;font-family:"Century Gothic","sans-serif";color:windowtext'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='margin-left:.5in'><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> re-wrenches-bounces@lists.re-wrenches.org [mailto:re-wrenches-bounces@lists.re-wrenches.org] <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<o:p></o:p></span></p></div></div><p class=MsoNormal style='margin-left:.5in'><o:p> </o:p></p><p class=MsoNormal style='margin-left:.5in'>Fellow Wrenches,<br><br>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>Kent Osterberg<br>Blue Mountain Solar<o:p></o:p></p></div></body></html>