batteries self study.ppt

Starting Batteries

• Each cell has a number of positive plates made of Lead Peroxide (Pb02)

• And negative plates of Lead (Pb)

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

• As batteries discharge the Sulfuric Acid (H2SO4)is turned to water (H2O) and the lead plates are turned into Lead Sulfate (PbSO4)

• 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

What happens as all the amps get used up?

• The electrolyte 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

• Deep Cycle batteries may not supply enough amp to run the starter while maintaining 10 Volts for the fuel injectors.

Starting Batteries

• The function of the battery is to start the engine•

They are not designed to slowly discharge. •

Some Recreational Vehicles use both a starting battery and a deep cycle battery.

•

The starting battery should be “isolated” from the deep cycle battery to keep it from long slow discharge when the engine is not running.

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.

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 should 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

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 –50F

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?

• Perform a battery capacity or “Load” test

• An undercharged battery will fail the load test

• Load testing an undercharged battery may lead to unnecessary battery replacement

Testing the battery state of charge with a volt meter

• Turn all electric loads OFF• (open circuit voltage)

• 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 crank the engine (without starting) for 15 seconds, or leave the headlamps on for two or three minutes

• Let the battery recover for fifteen 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

• (make sure key is OFF and doors closed to turn off all lights)

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 fifteen 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 the 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

Computer Memory

• Many computers “learn” to control idle speed, fuel trim, transmission shift points, etc.

•

Also the clock, radio stations etc. may be lost

• It may even have an anti theft radio that will not operate after a loss of power.

• Supplying an alternative power source (9 volts is enough) will avoid many problems.

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 16 volts and overheat the battery.

• If the battery has a shorted cell, the voltage may stay low however it will begin to gas excessively in that cell.

• 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 ONwhile 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 16 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 batteryHow 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 orBattery 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


• #3 Place a load (high amp draw) on the battery

• the load should be ½ the Cold Cranking Amp rating

• ...or three times the Amp Hour Rating of the battery

• usually around 200 to 250 amps…

• ...look it up to be sure


• #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.


• #5 If battery barely passes or fails the test…•...leave everything off for 15 minutes or longer.

• Recheck the open circuit voltage,

• if it is under 12.5 volts recharge and test again.


• 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.


• If the battery recovered to 12.6 volts…

• ... but dropped below 9.6 volts during the load test

• Recommend a new battery

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.

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

Check for Sulfated Battery

• Conduct 3 minute charge test…• …Unhook battery ground strap to protect computer• …(provide alternative power source to keep memory alive)

• ...fast charge for three minutes• …voltage should stay under 15.5V • …If voltage goes too high, the battery is sulfated• Find out the cause of the undercharged battery to prevent future problems with the replacement battery

What Causes Sulfation?

1) Undercharging

2) Starter Problems

3) Parasitic Draw using amps when key is OFF

Undercharging

• …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

Starter Problems

• Excessive starter amp draw

• Long cranking times

• Slow cranking speeds

• ….Check voltage drop across positive and negative battery cables during cranking

• starter cable should have less that 1/2 volt drop

Parasitic Draw

• Electric loads that do not turn off when the ignition key is removed will drain the battery

• Some parasitic draw is normal (computer memories, car alarms, etc.)

• Less than .050 amps (50 milliamps) is O.K.

• Some aftermarket alarms and radios may increase parasitic draw.

Corroded battery clamps

• 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

batteries self study.ppt

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