PS Magazine - TB 43-PS-665
PS, The Preventative Maintenance Monthly
ISSUE 665
APRIL 2008
19
PS 665
APR 08
Post-Charge Testing
You’ll need to
check the voltage
one more time before
using the batteries.
But your batteries
need to rest after
charging. Remove
the batteries from the
charger and allow
them to cool off
overnight if possible.
Batteries that are
heated from charging
may give incorrect
readings.
If battery OCV is above 12.85VDC and load voltage is above 10.80VDC after the
rest period, the battery can be reissued.
If a battery is below those readings, it needs additional charging. Battery disposal
is recommended if the battery still falls below 12.85V open circuit and 10.80V
loaded voltage after one additional 24-hour charging cycle.
NATO Slave Receptacle (24VDC) Charging
Connecting the charger to the vehicle’s NATO slave receptacle is another charging
option, but ensure all current drawing devices are OFF.
Like single battery charging, it is best to use a newer constant voltage charger,
with multiple charge settings. And if the charger has adjustable voltage output
capabilities, set it between 28.4VDC and 29.4VDC.
If the battery charger doesn’t have adjustments or switches (and is not a SMART
Charger, like the PulseTech brand) and output voltage is greater than 30.0VDC,
closely monitor the battery every 15 minutes during the ±rst two hours of
charging.
Charge batteries for 12 hours or longer. Severely depleted batteries (OCV less
than 10VDC) can take two to three days to recharge. If OCV voltage is not improved
(greater than 10VDC) after two days, it may never make a full recovery.
•
If the battery charger doesn’t
have adjustments or switches
(and is not a SMART Charger,
like the PulseTech brand) and
output voltage is greater than
15.0VDC, the battery should be
closely monitored, at least every
15 minutes, during the Frst two
hours of charging.
•
If the battery shows signs of
gassing, leakage, swelling, or
excessive heat when touching
the exterior as you charge, stop
charging right away!
Final Note on Battery Recovery
Many batteries require several diagnostic
pulsing cycles before they will take a charge. In
some cases, as many as ±ve cycles on a charger
may be required to begin to break down the
deposits built up on the cell plates.
Following this, you can usually connect the
battery to another charger with good results.
Often a rest period of several hours between
charges will also give positive results.
Batteries with voltages higher than 10 volts
charge without much dif±culty. On the other
hand, batteries with voltages between 4 and 10
volts often take multiple attempts to recover.
Once the battery begins to take current, it
usually does so quickly, however. Batteries
below 4 volts usually take a couple of days
before the chargers can diagnose the battery
condition and begin to recover the batteries.
You’re done charging when the charge current (amp meter on charger) drops to
less than
1
/
2
AMP per battery and holds there for 3 hours. Automatic chargers will
stop charging and give a screen reading of “Charge Complete”.
Test the batteries individually.
I’m a
smart
charger!
you gotta
man up!
if you don’t
improve in
2 days, you
may
never
make a full
recovery.
once you
charge me, let
me rest before
you check my
voltage again.
wh…what’s
up, doc?
I’d do this
for
free
,
but then I
couldn’t
charge
you.
you’re a
riot,
doc.
take these
life-saving
tips and
you’ll keep
current…
…in
more
ways
than
one!
your
voltage is
good now.
665.18-19.indd
1-2
3/2/08
3:49:44 PM
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