Greetings:
The thread about using Lead Acid Batteries has me concerned for those who
might choose to go this route for powering a Hercules II amplifier or a
radio.
Please read the following, save yourself some money, save your equipment,
save the environment.
First NEVER EVER connect a regulated power supply as a battery charger to a
battery without putting a SERIES connected diode with the output of the
regulated supply. You will only have the accident once and it will be
expensive, but if the regulated supply gets disconnected from the AC Mains
while the battery is connected to the supply the reverse current from the
battery back into the regulator circuit will blow up your regulator in the
Power Supply instantly. Put a large diode, or one arm of a diode bridge, in
series with the regulated supply output and connect to the battery.
Increase the regulated supply voltage output, there is usually an adjustment
somewhere to raise the voltage about .6 volts to overcome the effect of the
I^2R losses of the diode. Parts for these newer regulated supplies are hard
to get, be careful, failure to protect the regulated supply can be very
expensive instantly.
Second do the following to lower the maximum specific gravity of your lead
acid battery. You want to lower the maximum specific gravity of the battery
to drop the maximum capacity of the battery about 5 to 10%. This simple act
will stop or greatly reduce the battery becoming calcified, that is the nice
white hard stuff that forms on the battery plates and will kill your battery
for you. To do this when the battery is a full charge, use a battery
hydrometer and take out, of a more or less standard sized battery,100 to 150
Milliliters, 1/2 cup if your not into Milliliters, of acid from each cell.
reduce this acid to neutral by adding soda to it so it becomes ph neutral.
Get rid of the stuff that is left. Replace the amount of liquid removed
with distilled water. Use the battery some and then recharge it. This
simple reduction of the amount of acid will extend your battery life by two
or three times or more. The specific gravity at full charge will be about
.01 less than before. Calcification caused by the marketing department of
battery manufacturers demand for "high" performance kills almost every
battery made. Defeat these designed to fail conditions by removing a tiny
bit of the acid and greatly, by many times, extend the life of your battery.
Make absolutely sure that your battery charger has a way to cut off when the
battery is fully charged. Put a timer on the charger. If your using one of
these modern taper chargers that the manufacturer tells you can be left
connected to the battery for ever - be prepared to pay in $$ many times over
for this possible luxury. I usually open then use and rip them out, they
are designed by the same guys who want to put the extra strong acid in your
battery. Use a timer, cheap at twice the price, to manage your battery
charging cycle. If the battery charger people were into your interests at
heart then they would have put a very accurate terminal voltage adjust knob
on the charger so you could set the float voltage level to the specific
needs of a given battery. If the knob is not there, and it very rarely is,
then the marketing department is after you again.
Buy yourself a battery hydrometer. Manage the battery charge state by
managing the specific gravity of the battery. Get a 2 liter soft drink
bottle, plastic, cut the top off, and put a few inches of water in it and
keep your hydrometer washed out after using it. Dispose of the waste
material every year or so. Put the result in a bottle, neutralize with
soda, and then get rid of it.
The ACID used in a battery is the lowest form of H2SO4 that can be shipped
from the manufacturer of the ACID. It has every contaminent known to man in
it. This will never change. The issue here is that the ACID can be so
badly contaminated that it will eventually kill the battery anyways.
Contaminants are so many an varied that they are very hard to spot. If you
get a brand new battery that has no acid in it, consider making friends with
a high school chemistry teacher who can tell you were to get clean H2SO4 and
he/she should also supervise you in diluting the laboratory grade H2SO4 down
to the level the battery will need. This simple act will put your battery
on the road for double to quadruple life.
The only difference between a deep discharge battery and a regular
automobile battery is the amount of lead in the plates of the battery. The
deep discharge battery will have a greater plate size and thickness. IF YOU
HAVE DROPPED THE ACID LEVEL IN THE BATTERY AND YOU RARELY DISCHARGE THE LEAD
ACID BATTERY MORE THAN 20% OF CHARGE THEN YOU CAN LIVE WITH ANY CAR BATTERY
MADE WITHOUT ANY PROBLEMS. The operative word here is how far you discharge
the battery. If your into Contesting or long operating hours at a session
then the battery needs to be of the heavy duty type. If your into grabbing
a new country with the Amp ON then idle or off, then you have no need of a
deep cycle battery. Please remember that the starting motor of a car really
gives the car battery a nasty reminder when the multi hundred amp load hits
the battery. The survival trick is to make sure the battery is recharged
quickly which is what the alternator does in a car immediately after the
starting motor does its job of starting the engine.
If you are going to use a lead acid battery to start a car when the battery
has been left for some time at very cold conditions try this. Try to start
the car for about 30 seconds to one minute. Then get out of the car and
take a walk for 5 to 7 minutes. The battery will be in a state of large
chemical change after the heavy load put on by the starter motor. By
waiting a real clock measured 5 to 7 minutes, maybe up to 10 minutes, the
chemical reaction inside the battery of recovering from the attempt to start
the car will warm up the battery and get it ready to really work! After
waiting the real amount of time, and I am serious about the waiting period,
get in and try again, the car should start. I have used this trick at minus
40 (C or F they are the same at this point!) and it really works but you
have to wait the 5 to 10 minutes.
Make sure your battery charger will really take your battery up to the
needed terminal voltage to achieve a full charge. Failure to achieve a full
charge is the greatest killer of batteries known to man. I know people who
use a wall wart power supply to charge a car size battery. This is 99%
wrong. If your battery charger wont put out 3 to 5 amps at the terminal
voltage point then get one that will. Remember the goal to make the battery
last a long time is to charge it, measure the charge level with a
hydrometer, and then turn off the charger. If your battery is left
consistently with as little as 2% to 5% less charge than that needed you are
inviting the calcification of the plates and the eventual ruination of the
battery.
If you have an expensive battery that has bad calcification on the plates
the battery can be recovered sometimes. Here is the trick. Find a high
voltage water purification filter, I found several in a junk yard a while
back. Inside these things is a relay type vibrating assembly that pumps air
and a low pressure. Make up a manifold from the little air pump and a
separate tiny plastic tube that is wiggled down into the bottom of each cell
in the battery. I have used a 555 timer and stuff to turn the tiny
vibrating pump on and off at a rate of once a minute for about 4 seconds.
the air bubbles rising through the battery electrolyte will eventually,
sometimes, not if the acid is contaminated by some of the real bad chemicals
I mentioned above, break down the calcification. I have two 140 lb each 12
V batteries from a large diesel plant that I treated this way for two
years - they now will willingly deliver full performance in current to start
my diesel tractor after it has been sitting out doors during the winter.
The batteries have a replacement cost of over $270 US$ each, not bad for $5
worth of electricity and two years of watching the magic happen.
There is a common thought that keep the charge rate of a battery down and
there will be no smell. Yes this is right, there will also not be a full
charge on the battery either.
There is a price to pay for using a battery to replace a power supply that
would deliver the power needed to operate the radio or amplifier. THERE IS
NO FREE LUNCH. If you want to use a battery that is well and good, then you
must also put in the effort and care needed to look after the battery or the
economics you thought you were dealing with will not be working the way you
want them to work. Remember please THERE IS NO FREE LUNCH. I have talked
with amateurs who use batteries to replace large power supplies, until I
point out the economics of that decision and how to change the economics to
the amateurs advantage they thought they could just buy a battery and a
charger and that was it, sorry it doesn't work that way. Carefully work out
the amount of power consumed by the radio or amplifier, evaluate the work
associated with a battery and make an informed decision. You can PAY NOW OR
PAY LATER BUT YOU ARE GOING TO PAY!!! Beware of articles touting the value
and benefit of using a battery to replace an AC driven power supply. In the
latest issue of a popular back to the land magazine there is an article of
this type that pushes the value of a Battery based system. The writer
forgot to balance the applicable economic equation by pointing out the work
needed to look after the battery system. When you have an unbalanced
economic equation it is like the opportunity that is to good to be true, you
are about to get it put to you hard, real hard.
In closing, failure to vent a battery properly can cause enormous damage to
the equipment in the same room. I have a Swan 240 here that was kept in a
shack with a battery left on charge for months at a time. The radio is
largely dissolved. The surface is eaten off all the metal, copper wires
will fall off the terminals if they are touched, tube socket pins will break
off if they are touched, some of the glass tubes have all their pins eaten
almost or completely through. This occurred over a period of less than
three years and the acid out of two deep cycle batteries being boiled out of
them. It isn't pretty, it was terribly expensive for the chap who owned the
radio. Remember please - THERE IS NO FREE LUNCH.
Larry
VA3LK
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