[Milsurplus] Re: [armyradios] BB-490U from Fair Radio
Patricia Watkins
[email protected]
Wed, 15 Jan 2003 06:33:34 +0400
Hi All,
I have the batteries back on the charger, and the leds are blinkin, will =
leave them on until charged and repeat the load test. The first test =
was after the first charge cycle. The instructions (just read them) say =
that you can leave the batteries on for an additional 12 hours after the =
leds stop blinking. I will do that. The loads that I am using are 50 =
ohms across each of the 12 volt sections for a draw of .25 amps at 12V. =
Alan is correct in the 3/4 amp hours, but I had thought that the main =
problem was that these batteries would not take any charge at all. Will =
continue the experiment. I have built one of the pulse de-sulphation =
circuits that are on the web for re-juvinating deep cycle lead acid =
units for home power (solar). Wanted to see if it would work on a small =
mil lead acid battery. Interesting chemistries and problem when you =
start to get into this. Havin fun here in Oman.
Cheers,
John Watkins WD5ENU/A45XV
----- Original Message -----=20
From: Jim=20
To: [email protected]=20
Sent: Tuesday, January 14, 2003 7:51 PM
Subject: Re: [armyradios] BB-490U from Fair Radio
Patricia,
What was the resultant load resistance? 100 Ohms or 25 Ohms?
100 Ohms would result in a discharge of 0.12 Amp, for 3 hours that's =
about=20
0.36 AH capacity.
25 Ohms would result in a discharge of 0.5 Amp, for 3 hours that's =
about=20
1.5 AH capacity. About the same as a D cell!
Lead-Acid storage batteries, when stored discharged, go into a mostly=20
irreversible state called sulfate sulphation. so far, only very large =
stationary batteries (on the order of 500 to 1000 AH and larger) can =
be=20
somewhat reversed from a sulfphation condition, but at great expense =
of=20
electricity and time! Smaller batteries such as truck & car =
batteries and=20
smaller are mostly irreversible, regardless of efforts taken. =
Definitely=20
gel batteries are dead after sulphation.
Look at this web site for a little info on battery discharge and=20
ca[pacity.: <http://www.nrgresearch.com/oth/PsupLtgUnd.html>
I can't find the specs on these BB-490U batteries, but unless you have =
a=20
very low power hand held radio, these batteries of yours seem to be =
able to=20
qualify for the junk category!
Jim
----------
At 06:31 PM 1/14/03 +0400, you wrote:
>Hi All,
>
>I had noticed a few (read lots) of comments on the battery charger=20
>w/BB-490U batteries from Fair all being bad. I wanted to try an=20
>experiment with re-juvinating bad lead/acid cells, so I ordered a =
set. My=20
>daughter carried over my package from Fair radio with the charger and =
>batteries, and both of mine took a charge no problem (there goes the=20
>experiment). Thinking that it was just a surface charge, I hooked up =
a=20
>couple of 50 ohm 10 watt resistors (1/4 amp at 12v and proceeded to=20
>discharge them. Took a while (3 hours) for the voltage to go down to =
10.5=20
>volts with 2 very hot resistors. Both batteries are from Magnum =
Power=20
>Systems Ltd. in Marion NC, Date code is 01/91, contract no is=20
>N00140-90-D-BB32. Are these a different batch than everyone else=20
>received, or did I just get lucky.
>
>John WD5ENU/A45XV
>
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[Non-text portions of this message have been removed]
For current radio net info, see the bi-weekly net=20
announcement which is sent to you via e-mail.
The net schedule can also viewed at any time,=20
by going to:=20
http://groups.yahoo.com/group/armyradios/files/armynets.txt
The URL for the armyradios group at Yahoo is: =
http://groups.yahoo.com/group/armyradios
Community email addresses:
Post message: [email protected]
Subscribe: [email protected]
Unsubscribe: [email protected]
List owner: [email protected]
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