Download Linn-Benton Community College: Starting Batteries

Starting Batteries
How do batteries work?
Each cell has a number of positive plates
made of lead (sponge lead?)
And negative plates of ???
How do batteries work?
When the two dissimilar metal plates are
immersed in acid they create a voltage
This voltage is created by the concentrating
Negative Ions on the negative plates and
Positive Ions on the positive plates
How do batteries work?
As batteries discharge the acid is turned to
water and the lead plates are turned into
lead sulfate
When both plates are turned to lead sulfate the
battery is discharged or dead
How many volts does one battery cell produce?
2.1 volts
How many cells in a 12 volt battery?
6 cells
How many volts in a 12 volt battery?
12.6
How can you get 12.6 volts out of a bunch of 2.1
volt cells?
wire them in series
What comes out of a battery?
Electrical POWER
what is power?
Watts = volts X Amps
How do you get more volts out of a battery?
add more cells in series
How do diesel vehicles get 24 volts for starting
wiring 2-12 volt, or
4-6 volt batteries in series
What happens as all the amps get used up?
The electolyte turns to water and...
...the lead and sponge lead plates turn to Lead
sulfate and...
...the acid will no longer strip electrons from
the positive plates…
...and add them to the negative plates
The battery will go DEAD
How can we build a battery to supply more amps?
add more lead plates to each individual cell
more lead plates in a cell will increase…?
...cranking amps
…amp hour rating
So what battery should I use?
1) A battery with the proper voltage…
...6 volt, 12 volt, 24 volt
2) A battery with enough amp capacity...
…Cold Cranking Amps, or amp hour rating
3) A battery with that will fit in the carrier…
...BCI Group rating
BCI Group rating
How tall is the battery
How wide is the battery
How long is the battery
Where are the terminals located
If the battery is the correct BCI Group...
…is it correct battery?
NO! it must meet vehicle specific capacity
Manufacturer will specify a minimum CCA... or
Amp hour rating
Adding plates to a cell increases the amp capacity
Adding plates (surface area) will lengthen the service life of
the battery
Adding plates increases price.
Deep Cycle batteries
Some RV and Marine batteries are different
They are intended to operate smaller electrical loads
(lights, 12 volt accessories, trolling motors etc.) for
long periods of time without being recharged.
They are called Deep Cycle batteries as they can
withstand many cycles of long slow discharging
followed by long slow charging.
Deep Cycle batteries
Rapid discharging (like the hundreds of amps
pulled by a starter motor) will ruin a Deep
Cycle battery…
...it will overheat the plates.
Starting Batteries
The function of the battery is to start the engine
Then the generator will run all electrical loads.
Some Recreational Vehicles use both a starting
battery and a deep cycle battery.
The deep cycle battery is not hooked to the starter
motor.
Starting Batteries
If you allow a starting battery to slowly go dead it will
“SULFATE”
This happens when lead sulfate (formed when a
battery discharges) crystallizes on the surface of the
lead plates.
This will not allow the battery to fully recharge
Sometimes a sulfated battery will not recharge at all.
What type of battery do I sell
to the customer?
Proper BCI Group number
So it will fit in the vehicle
The proper type battery
Cranking or Deep Cycle
The more CCA the better
Make sure it meets the minimum
required by the manufacturer
When do I add battery Acid?
Only for filling dry charged batteries
Do not add acid to a battery already in service
Some batteries are assembled but the acid is left
out until it is ready for sale (Dry Charged)
The acid is added just before it is installed
in the vehicle
Storing Batteries
When a battery is new the lead and acid will begin to react and
it will slowly discharge.
Any battery that sits unused for several months will slowly go
dead and begin to sulfate.
This will ruin the battery..
All batteries be periodically recharged.
New batteries, awaiting sale, are given a “trickle charge” on a
regular schedule
What do I add to a battery with low electrolyte?
Distilled (or de-mineralized) water.
Adding tap water will encourage electrolysis
This will speed up the loss of that water when
charging and discharging
It will also encourage corrosion on the battery cables
How full do I fill the battery
Fill until the electrolyte just touches
the fill ring
Practice this…You can see just when it touches
If you overfill…You can pull the extra out…
…it your syringe is clean (use a hydrometer)
CLEAN CLEAN CLEAN
Be sure any item that touches the electrolyte
is washed
Clean battery hydrometer with plenty of water
after each use
How can I make the battery live longer?
1) make sure the battery hold down is solid
…vibration will knock material off the lead plates, lower the
amp capacity, and short out cells.
2) keep the battery clean
…as the battery cycles acid gets all over the case,
this will corrode the cables…
...and also provides a path for current to slowly discharge the
battery between terminals
(this can be measured with a volt meter)
2) Keep the battery clean
Always clean the battery with the vent caps on to
avoid contaminating the cells.
Baking soda and water works well to neutralize any
battery acid as do battery cleaning spray cans.
Rinse with lots of water after neutralizing the acid
Soap and water works great to clean a battery
How can I make the battery live longer?
3) keep the battery full…
...use distilled water and do not over fill.
If the battery is extra low check the charging system
for overcharging
If low electrolyte with no removable vent caps...
...replace the battery after double checking the
charging system.
How can I make the battery live longer?
4) Keep the battery fully charged…
...make sure the cables are not corroded
5) Check for parasitic drains ...
..A parasitic draw of up to .050 amps is acceptable.
6) Do not allow the battery to freeze…
...a dead battery can freeze at +15 F
…a fully charged battery will survive –50F
Frozen Batteries
DO NOT ATTEMPT TO JUMP START OR CHARGE A
FROZEN BATTERY
A charging battery forms Hydrogen gas that will be trapped by
the ice and can cause the battery to explode.
A frozen battery is ruined due to the ice breaking up the
sponge lead plates
Once thawed out it will soon fail.
Frozen Batteries
Replace frozen batteries.
A frozen battery will have a bulged out case
that will not reform
An overcharged battery can also cause the
case to bulge or distort.
If the case looks distorted test the battery and
the charging system
How can I test the battery?
#1) you can only accurately test a fully charged
battery
An undercharged battery might fail the load test
Load testing an undercharged battery may lead
to unnecessary battery replacement
How do I determine the battery
State of charge?
Use a hydrometer and compensate for the temperature
of the battery
As a battery discharges the acid turns to water
Acid is thicker and will float the hydrometer scale
higher
A fully charged battery cell has a “specific gravity” of
1.265 at 80 degrees
Hydrometer Testing
A colder battery will measure higher as cold liquid is thicker
A cold battery may look charged actually be undercharged
Check each cell…
…If the lowest cell is .050 points lower than the highest cell
the battery is defective
If water has just been added to the battery it will give a false
hydrometer reading
What if there are no removable vent caps?
Some batteries include a built in hydrometer.
This checks one cell only
Indicates the battery is at least 75% charged
when green (or not black/clear)
You can also test a battery state of charge with a
volt meter
Testing the battery state of charge
with a volt meter
12.6 V = a fully charged battery
12.4 V = 75% charged
12.2 V = 50% charged
My battery reads 13.2 Volts…
...Is it overcharged?
Some recombinant batteries maintain a slightly higher
open circuit voltage
Normal batteries will also register a surface charge.
This is not an accurate reading of the state of charge
How do I accurately get an
open circuit voltage reading ?
To remove the surface charge place a 250 amp load
on the battery, or crank the engine (without
starting) for 15 seconds,
Let the battery recover for five minutes, with the key
off and all accessories turned off.
A vehicle that has not been run for several hours will
have an accurate open circuit voltage reading
Do I really have to do all this
before testing the battery?
Only if the battery fails the load test
If the battery passes the capacity or load test…
...the battery is good.
If the battery fails the load (or capacity) test…
...let it sit for five minutes…
...recheck the open circuit voltage.
If voltage is below 12.6 volts, recharge the battery and run a
second load test
How do I recharge the battery?
The best way is with a slow (or trickle) charge.
Leave the charger unplugged when connecting the
battery, to avoid sparks and potential explosion
Batteries are most prone to explosion after load
testing, jump starting, or cranking th engine
Trickle charging will give the most complete charge
and is easiest on the battery
I don’t have time for a slow charge!
What’s wrong with quick charging?
Nothing…
... IF YOU FOLLOW SAFETY PRECAUTIONS…
…to protect the battery and the vehicle
To protect vehicle computers from high voltage...
...you should unhook the vehicle ground before
turning on the charger
What can go wrong when I
unhook the battery ground cable?
Insure the ignition key is turned off.
This will protect the computers from a voltage
spike when power is unexpectedly interrupted
Be sure to supply an additional power source to the
vehicle to protect the computer’s learned
operation strategy
Back to fast charging
Once the battery is isolated…
... you can turn the charger on high…
...after connecting the charging leads.
How long do I leave it on fast charge?
Leaving a battery on high charge is risky.
If it is sulfated the voltage will quickly rise above 15 volts and
overheat the battery.
Also if the battery has a shorted cell the voltage may stay low
it will begin to gas excessively
This will create hydrogen gas that may explode.
I take vent caps off when charging,
Is this O.K.?
Vent caps have built in flame arrestors
These can keep a battery from exploding
should sparks or flames come close
Leave the caps ON while charging
MONITOR the battery during a fast charge
How do I monitor the battery?
Check the voltage across the terminals with the charger on.
If it gets over 15 volts turn off the charger or slow the rate of
charge.
Feel the case of the battery,
if it gets hot it is overcharging
all batteries will get warm,
practice to know hot from warm
How do I monitor the battery?
Look listen and smell for gassing.
If you see lots of bubbles through the battery case
(white case) turn down the charger.
If you smell the gas, turn down the charger.
Leave the vent caps on.
Turn off and unplug the charger BEFORE removing
the charging cables from the battery.
Do I need to monitor the battery if
my charger has a voltage regulator?
Yes
A shorted cell in the battery will fool the
voltage regulator and may lead to damage
O.K. Now I have a charged battery
How do I tell if it’s any good?
The best test is the load or capacity test.
To perform this test you must measure battery
volts and amps
Load Testing or
Battery Capacity Testing
#1 hook up the test leads
#2 look up the capacity of the battery...
...that should be placed in that vehicle
It will be in Cold Cranking Amps…
...or in Amp Hours
Load Testing or
Battery Capacity Testing
#3 Place a load (high drain) on the battery
the load should be ½ the Cold Cranking Amp rating
...or three times the Amp Hour Rating of the battery
...look it up to be sure
Load Testing or
Battery Capacity Testing
#4 Watch the voltage of the battery.
It should not go below 9.6 volts within 15 seconds
do not load the battery longer than 15 seconds.
A strong battery will maintain 10 volts.
Load Testing or
Battery Capacity Testing
#5 If battery barely passes or fails the test…
...leave everything off for 5 minutes or longer.
Recheck the open circuit voltage,
if it is under 12.5 volts recharge and test again.
Load Testing or
Battery Capacity Testing
If the battery recovers up to 12.6 volts…
...and it barely passed the load test…
It is O.K., but close to the end of it’s service life
…Recommend replacement if in a cold climate.
Load Testing or
Battery Capacity Testing
If the battery recovered to 12.6 volts…
... but dropped below 9.6 volts during the load
test
Recommend a new battery
Load Test the Battery
Amp probe around either test cable
When must you isolate the battery?
Only when batteries are in parallel
How many volts for fully charged battery?
Is this battery over charged?
No! This is a surface charge.
How do you remove the surface charge?
Load battery to about 250 amps for 15 seconds
After loading, wait one or two full
minutes for the battery to recover
Is this battery fully charged?
Volt readings are not accurate without
External Leads
External Volt Meter Leads
Load Battery to ½ CCA
Is this a bad battery?
NO! You must select VOLTS EXTERNAL
What
½ Cold
Same
tells
Cranking
test
you with
thisAmps,
is
Volts
a good
External
Over
battery?
9.6 Volts,
15 seconds, Load is still ON
What do I do with the old,
junk battery?
Batteries contain hazardous lead
(and other nasty things)
They are very harmful to the environment.
It is illegal to place them in the trash or landfill.
What do I do with the old,
junk battery?
Any business that sells batteries…
... is legally obligated to recycle them.
This battery was only three years old,
what caused it to fail?
Vibration…
...Check hold down
Overcharging…
...look for bulged case, low electrolyte…
...voltage with engine running…
...after battery is fully charged
This battery was only three years
old, what caused it to fail?
Discharged (sulfated)
…look for dirty battery case…
…and corroded battery cable ends
Recommend more frequent battery cleaning
What Causes Sulfation?
…Check voltage drop across positive and
negative battery cables during cranking
should have less that 0.3 volts
Check for parasitic draw
Should have less than 50 milliamps
What Causes Sulfation?
…Check for low voltage with engine running
...after battery is fully charged
…Insure voltage stays up with all accessories
turned on and engine running at 2,000 RPM
…Quiz customer on driving habits…
...short trips will not allow battery to fully charge
Replace the entire battery cable
What is wrong with just replacing the cable end?
Shorter cables do not room for engine torque…
...and may pull on battery during acceleration
Corrosion often works down cable…
…and creates starting - charging problems
Connection at end of cable may provide unwanted voltage
drop
What
Corrosion
“Custom”
is wrong
onterminal
this
with
terminal
this
end
battery?
that may
cause voltage drop
Now you are The...
Battery Expert!