[RE-wrenches] Battery based hydrogen incidents

Wed Dec 15 10:42:12 PST 2010

Hello Jay,

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.

Dan

--- On Wed, 12/15/10, jay peltz <jay at asis.com> wrote:

From: jay peltz <jay at asis.com>
Subject: Re: [RE-wrenches] Battery based hydrogen incidents
To: "RE-wrenches" <re-wrenches at lists.re-wrenches.org>
Date: Wednesday, December 15, 2010, 12:04 PM

Hi Dan,
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.Never the less, why I use eye protection every time I go see batteries.

Jay
peltz power

On Dec 15, 2010, at 9:56 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 <kent at coveoregon.com> wrote:

From: Kent Osterberg
 <kent at coveoregon.com>
Subject: Re: [RE-wrenches] Battery based hydrogen incidents
To: "RE-wrenches" <re-wrenches at 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
OrzelGreat
Solar Works, IncE
- dana at 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-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at 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 

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