[450] battery backup project

[George Andrews]

Bob,

That is an excellent idea. Car batteries sit outdoors anyway. Have fun with 
the project!

George

----- Original Message ----- 
From: "Bob" <N1UJS at toast.net>
To: "144.450 Mailing List" <450 at lists.vhfwiki.com>
Sent: Monday, December 14, 2009 10:42 PM
Subject: Re: [450] battery backup project


> Your input has already led me to the plan of putting them in a box outside
> the window and cabling into the shack.....it's only a few feet away....
>
> ----- Original Message ----- 
> From: "George Andrews" <gandrews at ntplx.net>
> To: "144.450 Mailing List" <450 at lists.vhfwiki.com>
> Sent: Monday, December 14, 2009 10:30 PM
> Subject: Re: [450] battery backup project
>
>
>> Bob,
>>
>> Not a problem. I still push the envelope. Tried recharging a rechargeable
>> Lithium Ion battery in the last year. Got a little over confident in my
>> understanding of the rate of change of temperature. The AA battery went
>> bang. I had to get out the full face gas mask to get in the room! Had to
>> open the window and put a big fan in the window. It took three hours or 
>> so
>> before the air was of breathing quality. It took several hours more to
>> clean
>> up the debris. The AA battery was reduced to a large number of chunks,
>> none
>> bigger than gnat size. Glad no one or the cats were in the room at the
>> time.
>> It was enough to keep away from rechargeable LiIon batteries! I was
>> finding
>> pieces of the battery for six months afterwards.
>>
>> George
>>
>> ----- Original Message ----- 
>> From: <n1ujs at toast.net>
>> To: <450 at lists.vhfwiki.com>
>> Sent: Monday, December 14, 2009 6:34 PM
>> Subject: Re: [450] battery backup project
>>
>>
>>> Thanks for your input George.  Always good to hear
>>> from a man of science.  I tend to be more reckless in
>>> my "mad scientist" endeavors of course, but will take
>>> your warnings under advisement!
>>>
>>>
>>>
>>> ------- Original Message -------
>>> From    : George Andrews[mailto:gandrews at ntplx.net]
>>> Sent    : 12/13/2009 12:25:30 PM
>>> To      : 450 at lists.vhfwiki.com
>>> Cc      :
>>> Subject : RE: Re: [450] battery backup project
>>>
>>>
>>> Bob,
>>>
>>> I would only trickle charge the batteries as a
>>> routine (100 mA or less) once they are brought to
>>> full charge. Much better is to
>>> charge such batteries as needed. These do not appear
>>> to be SLA's, so there will
>>> be venting. What gets vented is Hydrogen gas
>>> (flammable, can have an explosive
>>> concentration issue and over time, years, will belch
>>> a very tiny amount of
>>> dilute sulfuric acid). Hydrogen flame is invisible
>>> unless it is burning
>>> something else. I would keep such a setup out in a
>>> well ventillated
>>> garage and consider the fact that car batteries can
>>> explode. Hydrogen
>>> builds up, there is an arc inside the battery or a
>>> source of ignition external
>>> to the battery. This will splatter the sulfuric acid
>>> over an area and on people
>>> if you happen to be nearby. Then there is the
>>> shrapnel from the battery
>>> case!
>>>
>>> I had a battery blow up in a 64 Chevy. It was a
>>> Sears battery with a year or so to go on the
>>> warranty. I thought I was the
>>> victim of a car bomb (radical politics days-thought
>>> the Birchers got me) and my
>>> ears were ringing for hours afterwards. The only
>>> idenfifiable part of the
>>> battery case was th botton inch or so and some of the
>>> lead plates. It was
>>> terrible decontaminating everything under the hood!
>>>
>>> The inverter will be expensive and might generate
>>> noise on HF.
>>>
>>> All my stuff is 12 V, including a CFL that lights
>>> up the shack.
>>>
>>> The 130 A/hr telcom batteries at the hamfest are a
>>> better idea.
>>>
>>> You could build a Schottky diode device to trickle
>>> charge and automatically switch over to battery on
>>> power failure.
>>>
>>> George
>>>
>>>  ----- Original Message ----- 
>>>  From:
>>>  Bob
>>>  To: 144.450 Mailing List
>>>  Sent: Sunday, December 13, 2009 11:44
>>>  AM
>>>  Subject: [450] battery backup
>>>  project
>>>
>>>
>>>  Successfully revived two Orbital batteries for
>>>  backup purposes.
>>>
>>>
>>>  Battery specs. are here:
>>>
>>> http://www.remybattery.com/Products/Exide-Orbital-ORB78DT-84-Starting-Battery__ORB78DT-84.aspx
>>>
>>>  The plan is to tie them together as a backup
>>>  supply for the entire shack in conjunction with an
>>> inverter (anyone got one
>>>  cheap to trade or sell?).
>>>  Total cash outlay so far, $18.00 ("core
>>>  value" for the two batteries).  They were new, but
>>> on the shelf at
>>>  work since '05.
>>>  They seem to be good as new after charging with
>>>  my Samlex APS 1215 (shown below, 15A cont., 20A
>>> surge) which will be devoted
>>>  to keeping them charged.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
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>>>
>>>
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>>>
>>
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