[RE-wrenches] Passive Battery Venting

[Jerry Shafer]

I do agree steel and copper/brass is to expensive for the possible return.
On Oct 28, 2014 4:10 PM, "Jerry Shafer" <jerrysgarage01 at gmail.com> wrote:

> We do what we can to seal the enclosure so if or when a battery fails and
> really gasses off the two vents on the same wall regardless of wind
> direction will vent the gas. If it is not sealed then the gas can travel
> through out the area this is not advised.
> On Oct 28, 2014 4:06 PM, "Ray Walters" <ray at solarray.com> wrote:
>
>>  That's an interesting idea, but all the failed designs they illustrate
>> don't show the way we usually do it.  We don't even bother with an inlet,
>> as most battery boxes have enough gap around the door to provide intake
>> air, then the exhaust comes off the top with several feet of rise to
>> prevent back drafting.  If its in any space that H2s may be a problem
>> (living space), we always add a Zephyr Power vent which has a back draft
>> preventer.  Even if the Zephyr fails, there will still be passive air flow
>> up the pipe past the fan.
>> I see 4 problems with their setup:
>> 1) Large Copper pipe is really expensive, and steel is hard to work with
>> and fittings are expensive.
>> 2) Metal pipe is not only thermally conductive, its also electrically
>> conductive.  I try to avoid unnecessary conductors in the battery box.
>> 3)  Metal pipe will corrode when exposed to H2S and battery acid.  That's
>> why we always use plastic.
>> 4) Their suggested pipe size (1" outside pipe) are way too small to
>> provide venting for any more than a couple of golf cart batteries.
>>
>> Basically, heat exchanger = good idea, but their version = not.
>>
>> As for the battery pass through connectors: they seem to be adding
>> unnecessary connections, and would also prevent using conduit.  I'd guess
>> they're not UL listed, so that whole idea is also code compliant.  Duct
>> seal will prevent the H2S from going up the conduit into the DC load center.
>>
>> They're trying to seal the box too much; the only time you could actually
>> have an explosive build up of H2S is if you sealed every gap on the battery
>> box.  I think its easier and safer to keep the gaps, and if your venting
>> fails, at least it won't blow up or over heat.
>>
>> R.Ray Walters
>> CTO, Solarray, Inc
>> Nabcep Certified PV Installer,
>> Licensed Master Electrician
>> Solar Design Engineer303 505-8760
>>
>> On 10/28/2014 4:28 PM, Drake wrote:
>>
>> Hello Wrenches,
>>
>> A client wants to use a passive battery venting method with a heat
>> exchanger to the outside for his bank of Full River AGM batteries. Below is
>> a link to one site that recommends this method. Has anyone used this
>> method?
>>
>>   http://www.bdbatteries.com/hydrogenventing.php
>>
>> My main concern for about the batteries is that they not get cold and
>> lose capacity during the short days when storage is most needed.
>>
>> He would also like to connect the terminals inside the box to a pass
>> through jumper http://www.bdbatteries.com/lugs.php?id=269 and then run
>> the cables, without conduit, to the inverter. As far as I know, conduit is
>> always required on the battery cables even if fuses are used in the battery
>> box. Has anything changed?
>>
>> Thanks,
>>
>> Drake
>>
>> Drake Chamberlin
>>
>>
>>
>>
>>
>> *Athens Electric LLC OH License 44810 CO License 3773 NABCEP Certified
>> Solar PV 740-448-7328 <740-448-7328> *http://athens-electric.com/
>>
>>
>>
>>
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