Re: [RE-wrenches] Battery based hydrogen incidents
Robb Cary was dealing with a lot of large scale telecomm systems with CD Technologies, so his scary photos were probably not from solar projects, (if that is any comfort!) He spoke of some projects with 50,000 2V industrial cells. I have worked with him for a long time and served on the board of Solar Sebastopol with him 5-6 years ago. I too have lost touch. I tried to reach him four or five years ago but his office said that he was retired and his cell number was disconnected. Nick Soleil Project Manager Advanced Alternative Energy Solutions, LLC PO Box 657 Petaluma, CA 94953 Cell: 707-321-2937 Office: 707-789-9537 Fax:707-769-9037 From: Darryl Thayer daryl_so...@yahoo.com To: RE-wrenches re-wrenches@lists.re-wrenches.org Sent: Wed, December 15, 2010 9:14:15 AM Subject: Re: [RE-wrenches] Battery based hydrogen incidents Yes they happen, Robb Cary of Battery Testing Co. has some frightening photos. I have lost contact with him however. I have had an experiance, but I did not take pictures. When you find the top of the battery and or battery enclousure blowen to smitherens it was a hydrogen explosion. Sorry I am on road today, would love to comment more. maybe later Darryl --- On Wed, 12/15/10, Warren Lauzon war...@wind-sun.com wrote: From: Warren Lauzon war...@wind-sun.com Subject: Re: [RE-wrenches] Battery based hydrogen incidents To: RE-wrenches re-wrenches@lists.re-wrenches.org Date: Wednesday, December 15, 2010, 11:05 AM In the 30+ years that we have been in the solar business, we have never seen or even heard of a single one. From: Dana Sent: Wednesday, December 15, 2010 9:10 AM To: 'RE-wrenches' Subject: [RE-wrenches] Battery based hydrogen incidents Ken – 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. 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. Q - How many battery based hydrogen incidents have happened in our collective experience? Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever belive anything, but seriously trust through action. From:re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kent Osterberg Sent: Tuesday, December 14, 2010 12:07 PM To: Wrenches Subject: [RE-wrenches] Battery Venting Fellow Wrenches, The discussion about battery venting reminds me of a useful and inexpensive program, BattMV, 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. Kent Osterberg Blue Mountain Solar ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org Northern Arizona Wind Sun - Electricity from the sun since 1979 Online Solar Store Free Solar Discussion Forum -Inline Attachment Follows- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org
Re: [RE-wrenches] Battery based hydrogen incidents
30+ years experience in solar off-grid battery backup systems, and 10 years before that designing and building heavy industrial battery-powered vehicles thatwere powered bytons of L-16 traction batteries. Here has been my experience: 1. Large industrial vehicle in corner of shop on charger, 30 feet away across shop a worker was grinding a weld and spark flew across shop and two L-16 batteries in bank exploded. Loudest sound I ever heard, but no fire. Lots of acid covered plastic chunks all over the place. Only tops of battery cells blew off, so no loss of acid. 2. A standard 12 volt RV/marine battery in small utility tool trailer which was kept charged by a 40 watt solar moduleblew off and caused acid damage to all wood walls and floor within 3 feet.After checking I found the battery was completely dry and all liquid electrolyte was gone. I think the lower cost charge controller went wako and kept on chargingfor days until all of the liquid had boiled off, then perhaps several of the cell plates warped from the heat and finally touched together causing a short and igniting the gasses building up inside the battery. 3. Two L-16 batteries sitting on shop floor and wired in series so I could re-charge with automotive shop type portable 12 volt charger. Charger had finished charging and shut off by timer switch. Although I knew better, instead of first un-plugging charger I "assumed" the alligator clips would no longer energized since the charger had timed off - wrong! When removing one of the clips there was a small spark and you could actually see the flame shoot out of the battery caps. Again, acid covered plastic pieces of the battery top all over and the loudest sound I ever heard but no fire. 4. I remember about 10 years ago seeing an article about a major battery room explosion. Best I can remember the entire metal building blew up and photos looked like a bomb hit the building. Article indicated the building was full of large industrial batteries that were poorly maintained and over-charged, and they thought the room had totally filled with hydrogen gas. Conclusions - The most likely place for an explosive level of hydrogen is INSIDE the batteries, not inside a well vented room or battery box, especially just after charging. However, wequit building battery boxes years agobecause the confinedbattery boxeswere always causing extensive battery terminal corrosion due to the higher concentrations of hydrogen and acid "mist" that settles all over the tops of the batteries in the confined space after repeated charging. Afterswitching to vented battery rooms we have had no other problems with corrosion and the batteries and terminals stay clean. Stay safe, and remember, if you "taste" something salty in the air whilestanding around in a battery room - get out! Jeff Yago Netscape. Just the Net You Need. ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Battery based hydrogen incidents
Here's a true story about another foolish but lucky guy. My Arkansas Ozark Mountain neighbor had a big 115 VDC windcharger and a battery bank of large 2-volt cells inside a shed at the base of his 85 feet tower. One day he opened the door with a smoke in his mouth. The H2 (not the batteries) exploded, rocketing him out the door, and knocking him on his ass. He was a big, strong guy and didn't get hurt, but he swore he would never smoke around batteries again. (Preventive action - ventilate battery room before entering.) - Original Message - From: Luke Christy To: re-wrenches@lists.re-wrenches.org Sent: Thursday, December 16, 2010 7:52 AM Subject: Re: [RE-wrenches] Battery based hydrogen incidents These descriptions of battery explosions certainly drive home the point that one should always always wear protective gear when working on batteries. I have a story that may take the prize for the most foolish behavior yet described (thankfully I wasn't involved until the cleanup stage). In 2008 a neighbor of mine was filling a bank of 12 L-16s installed in a remote home here in So. Colorado. Apparently it didn't occur to him that it probably wasn't a good idea to smoke while adding water to gassing batteries. Two or three batteries into the job, sure enough, a spark fell off his lit cigarette, probably landed in or near the open cap of the cell he was filling, and the resulting explosion blew the top off of the L-16, also spraying electrolyte everywhere in the battery room. My neighbor (who shall remain nameless) was not wearing protective gear of any kind, and of course he had acid in his eyes and all over his face. He was alone at this house, 40+ miles from the nearest town, and close to ten miles from the closest neighbor. He managed to wash his eyes and face in a creek, and was somehow able to drive the ten miles to the neighbor's house, who then took him to a hospital. Amazingly, he came out of it without permanent eye damage or scarring, but that must be due to having had more than his share of luck that day. I had the job of cleaning up the mess and replacing the blown-up battery. One thing that stood out was the fact that the top of the battery disintegrated into dozens of very sharp shards of plastic. These were obviously thrown out with the explosion and could have easily caused serious injury themselves. The entire wall of the battery room was covered with tiny bits of plastic, plate particles, and electrolyte, almost making a cartoon-like outline of my neighbor, as he had been standing in front of the wall when the battery blew. Always wear your eye protection. (and it seems that smoking plus hydrogen equals bad things). Luke Christy NABCEP Certified PV Installer™: Certification #031409-25 (Luke Christy) CoSEIA Certified PV Installer (Luke Christy) Solar Gain Services, LLC Monte Vista, CO. sgsrenewab...@gmail.com -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Battery based hydrogen incidents
Hi Dana, I've been 16 years all offgrid, no reports that I know of. jay peltz power On Dec 15, 2010, at 8:10 AM, Dana wrote: Ken – 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. 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. Q - How many battery based hydrogen incidents have happened in our collective experience? Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever belive anything, but seriously trust through action. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kent Osterberg Sent: Tuesday, December 14, 2010 12:07 PM To: Wrenches Subject: [RE-wrenches] Battery Venting Fellow Wrenches, The discussion about battery venting reminds me of a useful and inexpensive program, BattMV, 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. Kent Osterberg Blue Mountain Solar ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Battery based hydrogen incidents
Me neither, in 30 years! Jonathan Hill, solar applications engineerSierra Solar Systems563C Idaho Maryland RoadGrass Valley, CA 95945Celebrating our 30th year in solar!tech info and foreign orders:(530) 273-6754order line: (888) ON-SOLAR (US only)FAX:(530) 273-1760e-mail:mailto:solar...@sierrasolar.comworld wide web:http://www.sierrasolar.com On Dec 15, 2010, at 8:58 AM, jay peltz wrote:Hi Dana,I've been 16 years all offgrid, no reports that I know of.jaypeltz powerOn Dec 15, 2010, at 8:10 AM, Dana wrote:Ken –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.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.Q - How many battery based hydrogen incidents have happened in our collective experience?Dana OrzelGreat Solar Works, IncE -d...@solarwork.comV - 970.626.5253F - 970.626.4140C - 970.209.4076web -www.solarwork.com"Responsible Technologies for Responsible People since 1988"Do not ever belive anything, but seriously trust through action.From:re-wrenches-boun...@lists.re-wrenches.org[mailto:re-wrenches-boun...@lists.re-wrenches.org]On Behalf OfKent OsterbergSent:Tuesday, December 14, 2010 12:07 PMTo:WrenchesSubject:[RE-wrenches] Battery VentingFellow Wrenches,The discussion about battery venting reminds me of a useful and inexpensive program,BattMV, 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.Kent OsterbergBlue Mountain Solar___List sponsored by Home Power magazineList Address:RE-wrenches@lists.re-wrenches.orgOptions settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.orgList-Archive:http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.orgList rules etiquette:www.re-wrenches.org/etiquette.htmCheck out participant bios:www.members.re-wrenches.org___List sponsored by Home Power magazineList Address: RE-wrenches@lists.re-wrenches.orgOptions settings:http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.orgList-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.orgList rules etiquette:www.re-wrenches.org/etiquette.htmCheck out participant bios:www.members.re-wrenches.org___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Battery based hydrogen incidents
In the 30+ years that we have been in the solar business, we have never seen or even heard of a single one. From: Dana Sent: Wednesday, December 15, 2010 9:10 AM To: 'RE-wrenches' Subject: [RE-wrenches] Battery based hydrogen incidents Ken – 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. 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. Q - How many battery based hydrogen incidents have happened in our collective experience? Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever belive anything, but seriously trust through action. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kent Osterberg Sent: Tuesday, December 14, 2010 12:07 PM To: Wrenches Subject: [RE-wrenches] Battery Venting Fellow Wrenches, The discussion about battery venting reminds me of a useful and inexpensive program, BattMV, 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. Kent Osterberg Blue Mountain Solar ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org Northern Arizona Wind Sun - Electricity from the sun since 1979 Online Solar Store Free Solar Discussion Forum ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Battery based hydrogen incidents
Yes they happen, Robb Cary of Battery Testing Co. has some frightening photos. I have lost contact with him however. I have had an experiance, but I did not take pictures. When you find the top of the battery and or battery enclousure blowen to smitherens it was a hydrogen explosion. Sorry I am on road today, would love to comment more. maybe later Darryl --- On Wed, 12/15/10, Warren Lauzon war...@wind-sun.com wrote: From: Warren Lauzon war...@wind-sun.com Subject: Re: [RE-wrenches] Battery based hydrogen incidents To: RE-wrenches re-wrenches@lists.re-wrenches.org Date: Wednesday, December 15, 2010, 11:05 AM In the 30+ years that we have been in the solar business, we have never seen or even heard of a single one. From: Dana Sent: Wednesday, December 15, 2010 9:10 AM To: 'RE-wrenches' Subject: [RE-wrenches] Battery based hydrogen incidents Ken – 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. 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. Q - How many battery based hydrogen incidents have happened in our collective experience? Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever belive anything, but seriously trust through action. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kent Osterberg Sent: Tuesday, December 14, 2010 12:07 PM To: Wrenches Subject: [RE-wrenches] Battery Venting Fellow Wrenches, The discussion about battery venting reminds me of a useful and inexpensive program, BattMV, 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. Kent Osterberg Blue Mountain Solar ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org Northern Arizona Wind Sun - Electricity from the sun since 1979 Online Solar Store Free Solar Discussion Forum -Inline Attachment Follows- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
Re: [RE-wrenches] Battery based hydrogen incidents
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... From: Allan Sindelar Sent: Wednesday, December 15, 2010 11:10 AM To: re-wrenches@lists.re-wrenches.org Subject: Re: [RE-wrenches] Battery based hydrogen incidents Knowledge of two incidents - sort of. 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. 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. Otherwise, nothing. Allan Allan Sindelar al...@positiveenergysolar.com NABCEP Certified Photovoltaic Installer EE98J Journeyman Electrician Positive Energy, Inc. 3201 Calle Marie Santa Fe, New Mexico 87507 505 424-1112 www.positiveenergysolar.com On 12/15/2010 10:56 AM, Exeltech wrote: 38+ years in RE. Knowledge of one incident (an off-grid friend). 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. Had the incident occurred only minutes earlier, injuries could have resulted. He has since relocated his batteries to a dedicated (and vented) battery space. Dan --- On Wed, 12/15/10, Kent Osterberg mailto:k...@coveoregon.com wrote: From: Kent Osterberg mailto:k...@coveoregon.com Subject: Re: [RE-wrenches] Battery based hydrogen incidents To: RE-wrenches mailto:re-wrenches@lists.re-wrenches.org Date: Wednesday, December 15, 2010, 11:21 AM 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. Kent Osterberg Blue Mountain Solar Dana wrote: Ken – 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. 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. Q - How many battery based hydrogen incidents have happened in our collective experience? Dana Orzel Great Solar Works, Inc E - wlmailhtml:/mc/compose?to=d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever belive anything, but seriously trust through action. From: wlmailhtml:/mc/compose?to=re-wrenches-boun...@lists.re-wrenches.org [wlmailhtml:/mc/compose?to=re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kent Osterberg Sent: Tuesday, December 14, 2010 12:07 PM To: Wrenches Subject: [RE-wrenches] Battery Venting Fellow Wrenches, The discussion about battery venting reminds me of a useful and inexpensive program, BattMV, 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. Kent Osterberg Blue Mountain Solar ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re
Re: [RE-wrenches] Battery based hydrogen incidents
H2S is slightly heavier than air, but I vent with the inlets on line with the tops of the battery, and the outlet at the highest point. If there is a lot of space around the bottom of the batteries, I might lower the inlets some, but not enough for the airflow to contribute to much cooling effect. (I'm in the Rockies) All these stories make even more of a stickler about having my crews wear safety glasses. R. Walters r...@solarray.com Solar Engineer On Dec 15, 2010, at 12:08 PM, Jonathan Hill wrote: Ray- Is H2S lighter or heavier than air? Should it be vented from the top or bottom of the enclosure? Thanks. Jonathan Hill, solar applications engineer Sierra Solar Systems 563C Idaho Maryland Road Grass Valley, CA 95945 Celebrating our 30th year in solar! tech info and foreign orders: (530) 273-6754 order line: (888) ON-SOLAR (US only) FAX: (530) 273-1760 e-mail: mailto:solar...@sierrasolar.com world wide web: http://www.sierrasolar.com att6eade.png On Dec 15, 2010, at 10:48 AM, R Ray Walters wrote: I really think the real venting issue is H2S (hydrogen sulfide) gas, which is deadly at high enough concentrations, causes head aches at lower concentrations, and is just awful to smell at any concentration. I think you would have to literally design a battery box to explode to ever get to the 4% concentration necessary. It would consist of a large battery bank, ridiculously oversized charge source, the enclosure lid would be barely above the terminals, and the enclosure would be a refrigerator, or ice chest with excellent seals and gaskets all the way around. Hydrogen is tough to contain, it can permeate right through many plastics, metals, sheetrock, etc. Again despite article 480, the issue of venting is the H2S danger, and accelerated corrosion, not explosion. I too, have had a hydrogen explosion, ( and cool colorless fire after!) but it wasn't due to the enclosure venting at all. (short circuited battery, lead terminal melted through battery case, ignition of hydrogen inside of battery, boom, then jet whistle sound of fire burning through the hole) Article 480.9A should be revised from explosive mixture to dangerous mixture. H2S above 10ppm? I copied some toxicity info if anyone wants to see. R. Walters r...@solarray.com Solar Engineer Long-term, low-level exposure may result in fatigue, loss of appetite, headaches, irritability, poor memory, and dizziness. Chronic exposure to low level H2S (around 2 ppm) has been implicated in increased miscarriage and reproductive health issues among Russian and Finnish wood pulp workers,[11] but the reports have not (as of circa 1995) been replicated. 0.00047 ppm is the recognition threshold, the concentration at which 50% of humans can detect the characteristic odor of hydrogen sulfide,[12] normally described as resembling a rotten egg. Less than 10 ppm has an exposure limit of 8 hours per day. 10–20 ppm is the borderline concentration for eye irritation. 50–100 ppm leads to eye damage. At 100–150 ppm the olfactory nerve is paralyzed after a few inhalations, and the sense of smell disappears, often together with awareness of danger.[13][14] 320–530 ppm leads to pulmonary edema with the possibility of death. 530–1000 ppm causes strong stimulation of the central nervous system and rapid breathing, leading to loss of breathing. 800 ppm is the lethal concentration for 50% of humans for 5 minutes exposure (LC50). Concentrations over 1000 ppm cause immediate collapse with loss of breathing, even after inhalation of a single breath. On Dec 15, 2010, at 10:21 AM, Kent Osterberg wrote: 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. Kent Osterberg Blue Mountain Solar Dana wrote: Ken – 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. 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. Q - How many battery based hydrogen incidents have happened in our collective experience? Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever belive anything, but seriously trust through action. From: re-wrenches-boun...@lists.re-wrenches.org
Re: [RE-wrenches] Battery based hydrogen incidents
I have sold thousands of off-grid PV systems and hundreds of on-grid PV systems with batteries. In 1984, one customer located 30 miles north of New Orleans with an off-grid PV system and T-105 batteries reported that a battery exploded. The cause was a clogged cell cap vent that trapped H2 that was ignited by transient current from a nearby lightning strike (that also destroyed his charge controller). About 6 months later another nearby lightning strike fried another controller. The PV array was a few hundred feet from the home. The owner wired the PV array and home equipment ground rods together and made sure that cap vent holes were kept clean. Subsequent lightning storms caused no problems. The only exploded battery that I actually saw was also in the 1980s at a Sears service station. An automobile battery had exploded and tore a hole in the car engine hood. Joel Davidson - Original Message - From: Dana To: 'RE-wrenches' Sent: Wednesday, December 15, 2010 8:10 AM Subject: [RE-wrenches] Battery based hydrogen incidents Ken - 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. 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. Q - How many battery based hydrogen incidents have happened in our collective experience? Dana Orzel Great Solar Works, Inc E - d...@solarwork.com V - 970.626.5253 F - 970.626.4140 C - 970.209.4076 web - www.solarwork.com Responsible Technologies for Responsible People since 1988 Do not ever belive anything, but seriously trust through action. From: re-wrenches-boun...@lists.re-wrenches.org [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Kent Osterberg Sent: Tuesday, December 14, 2010 12:07 PM To: Wrenches Subject: [RE-wrenches] Battery Venting Fellow Wrenches, The discussion about battery venting reminds me of a useful and inexpensive program, BattMV, 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. Kent Osterberg Blue Mountain Solar -- ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org ___ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
