battery box fan [RE-wrenches]

[Bob Ellison, Alternative Energy Systems]

Jeff,
Yes it is all plastic and brushless so it can't cause a spark, however the
switch needs to be outside the container as they do spark.
The L-16's here used to gas enough that you could smell them real bad when
equalizing, even if it is not concentrated enough to explode, I don't think
we need to be breathing it.
I do it this way because the only battery vent fan that is available seems
overpriced and flimsy. If the general opinion is that they are not needed, I
will stop putting them in, but it seems like cheap insurance and things
smell better around here when equalizing!

Bob

-----Original Message-----
From:	Jeffrey Wolfe, Global Resources [mailto:global at sover.net]
Sent:	Sunday, November 26, 2000 10:36 PM
To:	'RE-wrenches at topica.com'
Subject:	RE: battery box fan [RE-wrenches]

I would caution that you should check out the components of the fan. Is it
all platic? Is there anything that "could" rub to create a spark? I quite
frankly think that it's a pretty extreme case where we get enough H2 from
an average battery bank to create an explosion (except in a very small
confined space with a local spark.) Howerver, if we're going to put in
battery vent fans, they ought to be "explosion proof". The Cone vent fans
have been "tested" although they are not "certified" or "listed" for this
purpose by anyone.

The only battery melt down experience I've been involved in was a *very*
large UPS for Digital Computer. Over 100 batteries. Brand new installation,
and the charger (large industrial type, I have no idea of the manufacturer)
failed in "charge" mode. Basically melted all the batteries. Room had a H2
sensor and a dedicated large fan for exhaust. H2 levels never got high
enough to trip the sensor, even though the battery salesman said it was the
closest he had ever seen to a complete battery failure.

So we put the fans in (except in tiny systems where we vent through the
wall w/o fan), but I don't particularly believe in the need. Anyone else
had experience with H2 accumulation?

Jeff

Jeffery D. Wolfe, P.E.
Global Resource Options, LLP
A Woman-Owned Vermont Limited Liability Partnership
4 Kibling Hill Road
P.O. Box 51
Strafford, VT 05072
802/765-4632
802/765-9983 (Fax)
global at sover.net
www.globalresourceoptions.com


----------
From: 	Bob Ellison, Alternative Energy Systems[SMTP:ellison at gisco.net]
Reply To: 	RE-wrenches at topica.com
Sent: 	Wednesday, November 22, 2000 1:00 PM
To: 	RE-wrenches
Subject: 	battery box fan [RE-wrenches]

For the last couple years I have been using a Radio Shack blower for
venting
battery boxes.
It is Cat. # 273-260
Described as a 12 volt DC brushless blower (Squirrel cage). The size is
3"x3"X1" Power consumption is .18 amp @ 12 volt
It turns @ 2600 rpm and is reverse polarity protected and according to the
diagram on the box it pushes over 8 CFM. With a SW inverter you can use a
relay to turn it on, otherwise I just put it on a lit switch (outside the
battery case) they can turn on when equalizing the batteries. I put the
blower into a piece of conduit and seal it with silicone to vent the gas
and
if the pipe rises enough it seems to self vent well enough for all but
equalizing the batteries.
Hint, DO NOT try to run it on 24 volt, it will not work and I just can't
seem to get the smoke back in the case!

The reason I am bringing this up is they're are discontinuing it and they
are $5.97 while they last.
You might want to check them out, they work nice.


Bob Ellison



- - - - - - -
To send a message:
 RE-wrenches at topica.com

The archive of previous messages:
 http://www.topica.com/lists/RE-wrenches/

To unsubscribe send a message to:
 RE-wrenches-unsubscribe at topica.com

To check out the other RE-Wrench participants:
 www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine:
 www.homepower.com

For info contact list moderator by email:
 michael.welch at homepower.com

___________________________________________________________
T O P I C A  http://www.topica.com/t/17
Newsletters, Tips and Discussions on Your Favorite Topics

- - - - - - -
To send a message:
 RE-wrenches at topica.com

The archive of previous messages:
 http://www.topica.com/lists/RE-wrenches/

To unsubscribe send a message to:
 RE-wrenches-unsubscribe at topica.com

To check out the other RE-Wrench participants:
 www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine:
 www.homepower.com

For info contact list moderator by email:
 michael.welch at homepower.com

___________________________________________________________
T O P I C A  http://www.topica.com/t/17
Newsletters, Tips and Discussions on Your Favorite Topics


- - - - - - -
To send a message:
 RE-wrenches at topica.com

The archive of previous messages: 
 http://www.topica.com/lists/RE-wrenches/

To unsubscribe send a message to: 
 RE-wrenches-unsubscribe at topica.com

To check out the other RE-Wrench participants:
 www.mrsharkey.com/wrenches/index.html

Hosted by Home Power magazine: 
 www.homepower.com

For info contact list moderator by email:
 michael.welch at homepower.com

___________________________________________________________
T O P I C A  http://www.topica.com/t/17
Newsletters, Tips and Discussions on Your Favorite Topics