From: MCCRYAW@YaleVM.YCC.Yale.Edu
Subject: Re: using cheaper car batteries
Organization: Yale University
Date: Tue, 13 Oct 92 18:54:30 EDT

In article <Bw2I0o.3or@ux1.cso.uiuc.edu>
rtaylor@ux1.cso.uiuc.edu (Roger Taylor) writes:
 
>
>If you are using a standard car battery to power a transceiver as I did
>for many years, put a computer 12 volt, 3 amp. power supply across it.
>Set the voltage output for 13.6 volts or whatever voltage you think your
>battery likes better.  The power supply will provide all the current
>on recieve and part on transmit.  The battery only supplies peak current
>for transmit.  With the voltage regulated PS, you won't overcharge the
>battery.  Since there is no deep discharge, unless you talk for 24 hours
>straight without receiving, the car battery does just fine and will last
>for many years.  You will probably have to clean the terminals occasionally.
>K9ALD
 
 
 An even cheaper alternative exists, one with some useful advantages, i.e. inst
ant recharge. At least one natonal auto mail order company offers a miracle goo
 that you just squeeze into each cell of your battery. This goo is notihng more
 than concentrated sulfuric acid, H2SO4, avaliable from any high school or coll
ege chemistry lab, or from your local chemical supply house. A few millilitres
of 10M (concentration in moles/liter) of this stuff in each of the cells of an
unsealed lead-acid battery will recharge it. The stronger the molarity M acid y
ou use, the least you need to use. AT least theoretically, if you used enough a
cid at the right concentration, you wouldnt even need to charge it!!!!! just a
quick burst of charge... 10-20 mins to get the electrolyte flowing agian......
You should be able to pick this stuff up for a few bucks, or even free. Try to
get about 1 litre (quart) of the stuff at about 10M concentration.
 
Dont come crying to me if this doesnt work or if something goes wrong. I used t
his procedure to keep my car battery for about an extra year (starvin'college s
tudents will do anything to save $$$)  *WARNING* sulfuric acid is highly corros
ive.... do this in open air and always add the acid slowly and in small amounts
 to the battery cells. DO NOT GET IT ON ANYTHING!!!! if you do rinse it off tho
uroughly with water and baking soda. if you get burned by it, you didnt hear ab
out this from me.
 
If youre interseted, the chemistry involved is mighty simple. In a discharged b
attery the sulfuric acid has formed lead sulfate on the lead plates of the batt
ery, leaving water as the electrolyte. Adding acid can reverse this process. Th
is will even work for a totally "dead" battery or one that has no electrolyte i
n it.... at least it should. By adding te acid, you allow the sulfate to go bac
k into acid, and the battery can be recharged.  Trickle charge it at first .
 
This presents some interesting possibilities to the field day or emergency oper
ator. At least theoretically :), you can add theright amount of acid to a disch
arged battery and  INSTANTLY recharge it.. kinda nice when you need 50 more qso
's and you have a dead battery.... I dont reccomend this more than a few times,
 because too much acid will just destroy the battery quickly. In an emergency,
however....... GOOD LUCK AND BE CAREFUL. I assume no responsibility for you or
your battery...
 
Ryan McCue    (licensed?   not  *yet*)
Yale University Amateur Radio Club  W1YU
 
Disclaimer? Nope. this is YALE. EVERYBODY  is liberal. somebody will agree with
me.