Steps to Recovering Lead
Acid Batteries
Deep cycling batteries
Equalization Charge
Electronic Battery Desulphator
Some of the following
procedures are also a component of battery maintenance but are in fact destructive
to some degree and
will decrease battery longevity. Longevity may not be a problem if the battery
performance is presently sub-optimal and you need to recover performance.
What
follows as a whole should not be considered preventative maintenance.
Restoring Sulfated batteries;
what has worked for us and our Clients is as follows:
Battery Recovery
You've determined that your
battery needs recovering. It will probably exhibit some or all of the
following:
- rapid voltage drop
under light loads,
- quickly taking on a charge,
- takes a long time to full
charge,
- higher temperatures during
charge and discharge,
- specific variance between
cells of .050 points or more.
A more detailed description of
the following steps follows below this section
- Label your each of the batteries and
each cell within a battery.
- Start a battery log and
continuously monitor your batteries with a good hydrometer (not a cheap one
from the automotive store or big box store You want a hydrometer that measures
to 3 decimal places). Keep track of individual
batteries and cells logging voltage, temperature and specific gravity.
Log all measurements after each process you put the battery through.
When the batteries are recovered, continue logging their attributes at least
once every three months.
- Purchase a good Hydrometer
if you don't have one.
- Put the batteries through an
Equalization charge cycle of your battery charger
- Immediately purchase or if
you are so inclined and to able, build an electronic Battery Desulphator and
connect it to your batteries and leave it there. Make sure you maintain a
maintenance charge on your batteries while the desulphator is running.
- Alternatively you can Deep Cycle the batteries.
Deep cycling is the process of fully charging your batteries then fully
discharging to a SG of 1.120 then fully charging the batteries to a SG of
about 1.27. Do this for at least six cycles.
- After two weeks repeat step 6 if specific gravity of cells continue to differ.
Do so again two
weeks later.
- If you have batteries or
cells that continue to differ from the rest look to replace them with good
ones, even good used ones of the same approximate age. Otherwise it may be time for a
new set of batteries. PLEASE read all the sections within our battery
section of which this is but one page. Your batteries came to this state for a
reason, our web pages within this section are there to help you to avoid
problems.
Good Luck!
Description of Battery
Recovery Methods and Technology and their Affect on the Batteries
Equalization Charge
During an equalization charge
peak voltage is raised, causing increased temperatures and vigorous gassing.
It is probable that gassing causes results from the overly high voltage
induced gassing causes turbulence over the sulfate crystals coating
the battery plates, dissolving most but separation of some allowing them to
float to the surface of the electrolyte. The higher temperatures
associated with equalization charging also help erode the battery plates, fresh
plate surface is exposed. The turbulence within the electrolyte also
stirs up and mix the electrolyte if it has become stratified. Never put a
discharged battery on Equalize. Equalize batteries after they have been
charged and allowed to cool down. The equalize option is not a charging method,
it is a maintenance technique used only when required.
Electronic Desulfation
Electronic current of up to 10A
cycled at 800 kHZ or more is applied to the batteries. This creates a resonance within
the batteries that wears down the sulfate crystals at an ionic level. The
resonance may adversely affect older batteries with structurally eroded plates
by causing fragile plate pieces to fall off and possibly short a cell.
Deep Cycling
A technique used to equalize
and rejuvenate where batteries are cycled between a full state of charge then
down to 20% state of charge. Recharging from 20% state of charge is
optimally performed at a charge rate of 10% of the ampere hour rating of the
battery array e.g. a 1500 AHr battery is charged with a charger capable of
charging at 150 Amps. The recharging sequence proceeds through the complete
three stage charging sequence of Bulk, Absorption and Float and charging should
be uninterrupted. Deep-cycling batteries reduces battery life but is less
destructive than an equalization charge. AGM and VRLA batteries cannot be
equalized but the deep cycling technique can be used.
Other Battery Recovery
Methods
We have surfed the Internet and
seen many other solutions suggested and followed some. From the cleaning of
battery sulphation through the use of a chemical referred to as
EDTA, or Ethylene diamine tetra acetic acid-tetrasodium salt. (N,N'-1,2-ethanediylbis
[N-(carboxymethyl) glycerine tetrasodium salt to removing sulphation deposits to
the use of TSP (after the electrolyte has been drained) to remove the other crud
out of batteries. We have no experience with the addition or use of
chemicals to batteries as all the manufacturers we represent do not recommend their
use.
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