Date: Mon, 16 Sep 1996 20:31:04 -0300 (ADT)
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: smitht@unb.ca (Tim Smith)
Subject: Car Battery FAQ 2.0
I had a large response for this, 16+ replies so far. Forgive me all you
others but this is easiest way to do it. There is a note on a deep cycle
battery FAQ site at the very bottom too, maybe for Westies/solar folks.
Tim Smith
>--- Forwarded message follows ---
>From: wdarden@mcimail.com (William Darden)
>Subject: Car Battery Frequently Ask Questions 2.0
>Date: 9 Sep 1996 11:35:14 GMT
>
>
>
> CAR BATTERY FREQUENTLY ASKED QUESTIONS 2.0
> September 8, 1996
>
>
>A word of caution. Batteries contain a sulfuric acid electrolyte which is
>a highly corrosive poison, that will produce gasses when recharged and
>explode if ignited. This will hurt you--BAD! When working with
>batteries, you need to have plenty of ventilation, remove jewelry, wear
>protective clothing and eye wear, and exercise caution. Whenever
>possible, please follow the manufacturer's instructions for testing,
>jumping, installing and charging. This FAQ assumes a six cell, 12 volt
>negatively grounded system found in most cars, light trucks or vans.
>
>The technical stuff is in [brackets].
>
>
>CONTENTS
>
> 1. WHAT IS THE BOTTOM LINE?
> 2. WHY BOTHER?
> 3. HOW DO I PERFORM PREVENTATIVE MAINTENANCE?
> 4. HOW DO I TEST A BATTERY?
> 5. HOW DO I KNOW IF THE CHARGING SYSTEM IS OK?
> 6. HOW DO I JUMP START MY CAR?
> 7. WHAT DO I LOOK FOR IN BUYING A NEW BATTERY?
> 8. HOW DO I INSTALL A NEW BATTERY?
> 9. HOW DO I RECHARGE MY BATTERY?
> 10. WHAT IS PARASITIC LOAD?
> 11. HOW CAN I INCREASE THE LIFE OF MY BATTERY?
> 12. WHAT ARE THE MOST COMMON CAUSES OF PREMATURE BATTERY
> FAILURES?
> 13. WHAT ARE THE MYTHS ABOUT BATTERIES?
> 14. WHERE CAN I FIND MORE INFO ON BATTERIES?
>
>
>1. WHAT IS THE BOTTOM LINE?
>
> A. Perform regular preventative maintenance, especially during HOT
>weather and before COLD weather, (See Section 3)
>
> B. Remove surface charge before load testing and check the specific
>gravity in each cell and the terminal voltage, (See Section 4)
>
> C. Keep the battery charged, but do NOT overcharge, (See Section 9)
>
> D. Buy the freshest and largest Reserve Capacity (RC), non-sealed
>battery that will physically fit with a Cold Cranking Amp (CCA) rating for
>your climate that meets or exceeds the car's Original Equipment
>Manufacturer's (OEM) cranking amp requirement, and (See Section 7)
>
> E. Retest after deep discharges or jump starts for latent damage.
>(See Section 4)
>
>
>2. WHY BOTHER?
>
>Because only the rich can afford cheap batteries.....
>
>A good quality battery will cost between $50 and $100 U.S. and, if
>properly maintained, it should give you an average of five years of
>service. The primary purpose of a car battery is to start the engine,
>filter or stabilize the power, and provide extra power for the ignition,
>lighting and other accessories when their combined load EXCEEDS the
>capability of the charging system, i.e., when the engine is idling.
>Secondarily, a car battery provides power to the electrical system when
>the charging system is not operating.
>
>A battery "ages" as the active plate material sheds (or flakes off) due
>to the expansion and contraction that occurs during the discharge and
>recharge cycles. Deep discharges, heat and vibration accelerate this
>"aging" process. Eventually, the sediment builds up and the cell shorts
>out or the active material in the plates can no longer sustain a discharge
>current and the battery "dies". In a hot climate, the harshest
>environment for a battery, a recent survey of junk batteries revealed that
>the AVERAGE life of a good qualify battery was 37 months, whereas, for a
>poor quality battery, it was 23 months. Slow cranking, especially on a
>cold day, is another good indication that your battery is going bad and it
>should be tested.
>
>Deeply discharged batteries almost always occur at the most inopportune
>times, e.g., AFTER you have jump started your car, at the airport
>returning home from a long trip, during bad weather, late at night in a
>dark parking lot, or when you are late for an appointment. You can easily
>spend the cost of a new battery or more for an emergency jump start or
>tow.
>
>Most of the "defective" batteries returned to the manufacturer are good.
>This suggests that most SELLERS of new batteries do not know how to
>properly test batteries.
>
>
>3. HOW DO I PERFORM PREVENTATIVE MAINTENANCE?
>
>Maintaining the correct electrolyte levels, tightening loose hold-down
>clamps and terminals, removing corrosion, and checking the alternator
>belt tension is normally the ONLY preventative maintenance required for
>a battery. The preventive maintenance frequency is dependent upon climate
>and battery type, but you should perform at least once before cold weather
>starts and once a month in hot weather.
>
>If the electrolyte levels are low, add DISTILLED water to the level
>indicated by the battery manufacturer or to 1/8" BELOW the bottom of the
>filler tube (vent wells). DO NOT OVERFILL, especially in hot climates!
>
>
>4. HOW DO I TEST A BATTERY?
>
>The are four simple steps to test a car battery--inspection, remove
>surface charge, state-of-charge test and load test. To test a battery
>(or to troubleshoot charging or electrical systems), you will need a
>digital voltmeter with .5% or better accuracy. A digital voltmeter can be
>purchased at an electronics store and will cost between $20 and $200 U.S.
>If you have a non-sealed battery, you will need a temperature compensating
>hydrometer which can be purchased at an auto parts store for approximately
>$5 U.S.
>
> A. INSPECTION
>
>Visually inspect for obvious problems, e.g., loose alternator belt, low
>electrolyte, corroded cable or terminal clamps, loose hold-down clamps or
>cable terminals, or a damaged case.
>
> B. REMOVE SURFACE CHARGE
>
>If you have just recharged you battery or driven your car, eliminate any
>surface charge by one of the following methods; otherwise, go to the next
>step:
>
> 1. Allow the battery to sit for two to three hours,
>
> 2. Turn the headlights on high beam for five minutes and
> wait five minutes, or
>
> 3. With a battery load tester, apply a load at one half the
> battery's CCA rating for 15 seconds and wait five minutes.
>
> C. STATE-OF-CHARGE TEST
>
>Using the following table, determine the battery's state-of-charge:
>
> Open Circuit Approximate Average Cell
> Battery Voltage State-of-charge Specific Gravity
>
> 12.65 100% 1.265
>
> 12.45 75% 1.225
>
> 12.24 50% 1.190
>
> 12.06 25% 1.155
>
> 11.89 0% 1.120
>
>[If the temperature of the electrolyte is below 70 degrees F (21.1 degrees
>C), then add .012 volts (12 millivolts) per degree below 70 degrees F to
>the reading.]
>
>Check both the specific gravity in each cell with a external hydrometer
>AND the battery terminal voltage with a digital voltmeter without the
>engine running. For sealed batteries, measuring the battery's voltage
>without the engine running with a digital voltmeter is the only way you
>can determine the state-of-charge. Some batteries have a built-in
>hydrometer which only measures the state-of-charge in ONE of it's six
>cells. If the indicator is clear or light yellow, then the battery has a
>low electrolyte level and should be refilled before proceeding, or if
>sealed, the battery should be replaced.
>
>If the state-of-charge is BELOW 75% using either the specific gravity or
>voltage test or the built-in hydrometer indicates "bad" (usually dark),
>then the battery needs to be recharged BEFORE proceeding. Replace the
>battery, if one or more of the following conditions occur:
>
> 1. If there is a .050 or more difference in the specific
> gravity reading between the highest and lowest cell, you
> have a weak or dead cell(s),
>
> 2. If the battery will not recharge to a 75% or more
> state-of-charge level or if the built-in hydrometer still
> does not indicate "good" (usually green, which is 65%
> state-of-charge or better),
>
> 3. If digital voltmeter indicates 0 volts, you have an open
> cell, or
>
> 4. If the digital voltmeter indicates 10.45 to 10.65 volts,
> you have a shorted cell. [A shorted cell is caused by
> plates touching, sediment build-up or "treeing" between
> plates.
>
> D. LOAD TEST
>
>If the battery's state-of-charge is at 75% or higher or has a "good"
>built-in hydrometer indication, then load test the battery by one of the
>following methods:
>
> 1. Turn the headlights on high beam for five minutes,
>
> 2. Disable the ignition and turn the engine over for 15
> seconds with the starter motor,
>
> 3. With a battery load tester, apply a load equal to one half
> of the CCA rating of the battery for 15 seconds, or
>
> 4. With a battery load tester, apply a load equal to one half
> the OEM cranking amp specification for 15 seconds.
>
>DURING the load test, the voltage on a good battery will NOT drop below
>9.7 volts with the electrolyte at 80 degrees F (26.7 degrees C). [If the
>electrolyte is above 80 degrees F, add .1 volt for every 10 degrees above
>80 until you reach 100 degrees. If below 80 degrees F, subtract .1 volt
>for every 10 degrees until 40 degrees.] After the load is removed, wait
>five minutes and the battery should "bounce back" to the 50%
>state-of-charge level or above. If the battery drops below minimum test
>voltage, does not bounce back, or will not start the engine, then you
>should replace it. If the battery passes this test, you should recharge
>it to restore it to peak performance.
>
>
>5. HOW DO I KNOW IF MY CHARGING SYSTEM IS OK?
>
>A car's charging system is composed of an alternator (or DC generator), a
>voltage regulator, battery and indicator light or gauge. While the engine
>is running, it's purpose is to provide power for the car's electrical
>load, e.g., ignition, lighting, accessories, etc., and to recharge the
>car's battery.
>
>When the charging system fails, usually an indicator light will come on or
>the gauge will not register "good". The most common charging system
>failure is a loose, worn or broken alternator belt, so check it first. If
>OK, then with a known good battery and the engine running at 2000 RPM or
>more for two minutes, depending on the load and ambient temperature, the
>voltage should increase to between 13.0 and 15.1 volts. Most cars will
>measure between 14.0 and 14.5 volts on a warm day. [Most voltage
>regulators are temperature compensated to properly charge the battery
>under different environmental conditions. As the ambient temperature
>decreases, the charging voltage is increased to overcome the higher
>battery resistance. Conversely, as the ambient temperature increases,
>the charging voltage is reduced. Other factors affecting the charging
>voltage are the battery's condition, state-of-charge, electrical load and
>electrolyte level and purity.]
>
>If terminal voltage is below 13.0 volts and the battery tests good after
>being externally recharged or if you are still having problems keeping it
>charged, then have the charging system's output voltage and current and
>car's parasitic (key off) load tested. A loose alternator belt or bad
>diode will significantly reduce the alternator's current output.
>
>If output voltage is above 15.1 volts with the ambient temperature above
>freezing, the battery's electrolyte level is frequently low, or you smell
>"rotten eggs" around the battery, then you are probably overcharging the
>battery and the charging system should be tested.
>
>
>6. HOW DO I JUMP START MY CAR?
>
>In cold weather, a good quality booster cable with four to six gauge wire
>is necessary to provide enough current to the disabled car to start the
>engine. [The smaller the wire gauge number, i.e., the larger the wire
>diameter, the better.] Please check the owner's manual for BOTH vehicles
>BEFORE attempting to jump start and follow the manufacturer's procedure
>because some cars should not be running during a jump start. However,
>starting the disabled car with the good car running can prevent having
>two disabled. DO NOT allow the booster cable clamps touch each other or
>the POSITIVE clamp to touch the frame or engine block.
>
> A. If BELOW freezing, determine that the electrolyte is NOT frozen
>in the dead battery. If frozen, allow to thaw BEFORE proceeding. A
>discharged battery, i.e., battery voltage or 12.0 volts or less or
>specific gravity of 1.140 or less, will freeze at approximately 8
>degrees F (-15 degrees C).
>
> B. Without the cars touching, turn off all unnecessary accessories
>and lights on BOTH cars and insure there is plenty of ventilation.
>
> C. Start the car with the good battery and let it run for at least
>two or three minutes at fast idle to recharge it's battery BEFORE
>proceeding.
>
> D. Connect the POSITIVE booster cable clamp (usually RED) to the
>POSITIVE terminal on the dead battery. Connect the POSITIVE booster
>cable clamp on the other end of the booster cable to the POSITIVE terminal
>on the good battery.
>
> E. Connect the NEGATIVE booster cable clamp (usually BLACK) to the
>NEGITIVE terminal on the good battery and the NEGATIVE booster cable clamp
>on the other end to a clean, unpainted area on the engine block or frame
>on the disabled car AWAY from the battery.
>
> F. Let the good car to continue to run at high idle for five minutes
>OR MORE to allow the dead battery to receive some recharge and to warm
>it's electrolyte.
>
> G. Start the disabled car and allow to run at high idle. If the car
>does not start the first time, recheck the connections, wait a few minutes
>and try again.
>
> H. Disconnect the booster cables in the REVERSE order, starting with
>the NEGITIVE clamp on the block or frame of the disabled car to minimize
>the possibility of an explosion.
>
> I. As soon as possible, fully recharge and test the dead battery
>for latent or permanent damage as a result of the deep discharge.
>
>
>7. WHAT DO I LOOK FOR IN BUYING A NEW BATTERY?
>
>Battery buying strategy for use in Canada, for example, is different than
>hot climates that you find in Texas. In the colder climates, higher CCA
>ratings are more important; whereas, in a hot climate, a higher RC ratings
>are more important once the CCA rating has satisfied the OEM cranking amp
>requirement.
>
> A. Cold Cranking Amps (CCA)
>
>The most important consideration is sizing the battery's CCA rating to
>MEET OR EXCEED, depending on the climate, the car's OEM cranking
>requirement. [CCAs are the discharge load measured in amps that a fully
>charged battery at 0 degrees F (-17.8 degrees C) can deliver for 30
>seconds and while maintaining the voltage above 7.2 volts. Batteries are
>sometimes advertised by their Cranking Performance Amps (CA) or Marine
>Cranking Amps (MCA) measured at 32 degrees F (0 degrees C) or Hot Cranking
>Amps (HCA) measured at 80 degrees F (26.7 degrees C), which are not the
>same as CCA. Do not be mislead by CA, MCA or HCA ratings. To convert CAs
>to CCAs, multiply the CAs by .8. To convert HCAs to CCAs, multiply HCAs
>by .69.]
>
>In hot climates, buying batteries with double or triple the CCA ratings
>that exceed the OEM requirement is a WASTE of money. However, in colder
>climates the higher CCA rating the better, due to increased power
>required to crank a sluggish engine and the inefficiency of the cold
>battery. As batteries age, they are less capable of producing CCAs.
>
>One of the major battery manufacturers, Exide, publishes the following
>table:
>
> Available Power Temperature Power Required
> From Battery degrees F To Crank Engine
>
> 100% 80 100%
>
> 65% 32 155%
>
> 40% 0 210%
>
> 25% -32 350%
>
>[If more CCA capacity is required, two (or more) 12 volt batteries can be
>connected in parallel. Within a BCI group size, generally the battery
>with more CCA will have more plates because a larger surface area is
>required to produce the higher current.]
>
> B. Reserve Capacity (RC)
>
>The second most important consideration is the Reserve Capacity rating
>because of the effects of an increased parasitic (key off) load and in
>emergencies. [RC is the number of minutes a fully charged battery at 80
>degrees F (26.7 degrees C) can be discharged at 25 amps until the voltage
>falls below 10.5 volts.] More RC is better in every case! In a hot
>climate, for example, if your car has a 360 OEM cranking amp requirement,
>then a 400 CCA rated battery with 120 minute RC with more electrolyte
>would be more desirable than one with 1000 CCA with 90 minutes of RC.
>
>[If more RC is required, two six volt batteries can be connected in series
>or two (or more) 12 volt batteries can be connected in parallel. Within a
>BCI group size, generally the battery with larger RC will weigh more
>because it contains more lead.]
>
> C. Type
>
>The two most common types of CAR batteries are low maintenance
>(non-sealed) and maintenance free (non-sealed or sealed). [The low
>maintenance batteries have a lead-antimony/calcium (dual alloy or hybrid)
>plate formulation; whereas, the maintenance free batteries have a
>lead-calcium/calcium formulation.] The advantages of maintenance free
>batteries are less preventative maintenance, longer life, faster
>recharging, greater overcharge resistance, reduced terminal corrosion and
>longer shelf life, but are more prone to deep discharge (dead battery)
>failures. In hot climates, buying non-sealed batteries is recommended
>because a sealed battery will NOT allow you to add water when required or
>to test the specific gravity with an external hydrometer.
>
>Some manufacturers introduced a third type of car battery, "dual", that
>combined a standard battery with switchable emergency backup cells. For
>about the same cost a better approach was to buy two batteries and isolate
>them.
>
>For off road applications in trucks, recreational vehicles (RVs), 4x4s,
>vans or sport utility vehicles, some manufacturer's distribute "high
>vibration" or RV battery versions designed to reduce the effects of
>moderate vibration. For excessive vibration applications, it is best to
>buy a commercial battery.
>
>Car batteries are specially designed for high initial cranking amps
>(usually for five to 15 seconds) to start an engine; whereas, deep cycle
>(or marine) batteries are designed for prolonged discharges at lower
>amperage. A "dual marine" battery is a compromise between a car and deep
>cycle battery; however, a CAR battery will give you the best performance
>in a CAR. For RVs, a car battery is used to start the engine and a deep
>cycle battery is used to power the accessories. [The batteries are
>connected to a diode isolator and both are automatically recharged by the
>RV's charging system when engine is running. For additional information
>on multi-battery applications, call (800) 845-6269 or (503) 692-5360 and
>request a free copy of "Introduction to Batteries and Charging Systems" by
>Ralph Scheidler.]
>
> D. Size
>
>Manufacturers build their batteries to an internationally adopted Battery
>Council International (BCI) group number (24, 26, 70, 75, etc.)
>specification, [which is based on the physical case size, terminal
>placement and terminal polarity.] The OEM battery group number is a good
>starting place to determine the replacement group. Within a group, the
>CCA and RC ratings, warranty and battery type will vary in models of the
>same brand or from brand to brand. Batteries are generally sold by model,
>so the group numbers will vary for the same price. This means that for
>the SAME price you can potentially buy a physically larger battery with
>more RC than the battery you are replacing, e.g. a 34/78 group might
>replace a smaller 26/70 group and give you an additional 30 minutes of RC.
>If you do this, be sure that the replacement battery will fit, the cables
>will connect to the correct terminals, and that the terminals will NOT
>touch the hood when closed.
>
>BCI and the battery manufacturers publish application guides that will
>contain the OEM cranking amperage requirements and group number
>replacement recommendations by make, model and year of car, and battery
>size, CCA and RC specifications. Manufacturers might not build or the
>store might not carry all the BCI group numbers. To reduce inventory
>costs, dual terminal "universal" batteries that will replace several group
>sizes are becoming more popular and fit 75% or more of cars on the road
>today.
>
>Battery manufacturers or distributors will often "private label" their
>batteries for large chain stores. Below is a list of the largest domestic
>battery manufacturers/distributors in North America and my understanding
>of some of their brand names and private labels.
>
> Johnson Controls Inc. (JCI)
> Ameriton
> Duralast (Contact local Auto Zone store)
> Energizer (Contact local Target store)
> Eveready (800-331-9926 or contact local Costco store)
> Interstate (800-272-6548)
> Motorcraft (800-392-3673)
> Power Connection
> older Sears Diehards
>
> East Penn (610-682-6361)
> American
> Electro
> Deka
> Hi-Tech
> Pow-R-Surge
>
> Douglas (800-368-4527)
> Farmland (Contact local store)
>
> AC Delco/Delphi (800-223-3526)
> Diehard Gold (Contact local Sears store)
> Double Eagle (Contact local Firestone store)
> Dura Power
> Everstart (Contact local Wal-Mart store)
> Freedom (Contact local Sears store)
> Lastcell (Contact local Trac Auto store)
> Tough One (Contact local Western Auto store)
> Voyager
>
> GNB (800-242-6750)
> Champion (Contact local Sams store)
> Omaga (800-925-6278 or contact local Wal-Mart store)
> Voyager (Contact local Sams store)
>
> Exide (800-346-3760)
> Auto Express (Contact local Wards store)
> Centura (Contact local K-Mart store)
> DieHard non-Gold (Contact local Sears store)
> Edge
> Legend (800-538-6272 or contact local NAPA store)
> Motorvator (Contact local K-Mart store)
> Power-Tron
> Prestolite (Contact local HiLo store)
> Pro Start (Contact local Pep Boys store)
> Quick Start (Contact local Wards store)
> Sears (Contact local store)
> Titan
> Value-Lite (Contact local Firestone store)
>
> E. Freshness
>
>Determining the "freshness" of a battery is sometimes difficult. NEVER
>buy a battery that is MORE than SIX months old because it is starting to
>sulfate. [Sulfation occurs when lead sulfate can not be converted back to
>charged material and is created when discharged batteries stand for a long
>time or from excessive water loss.] The date of manufacture is stamped on
>the case or printed on a sticker. It is usually a combination of alpha
>and numeric characters with letters for the months starting with "A" for
>January (skipping "I") and digit for the year, e.g., "J6" for September,
>1996. Like bread, fresher is definitely better.
>
> F. Warranty
>
>As with tire warranties, battery warranties are NOT necessarily indicative
>of the quality or cost over the life of the car. Most manufacturers will
>prorate warranties based on the LIST price of the bad and replacement
>battery, so if a battery failed half way or more through its warranty
>period, buying a NEW battery outright might cost you less than paying the
>difference under a prorated warranty. The exception to this is the free
>replacement warranty period. This represents the risk that the
>manufacturer is willing to assume. A longer free replacement warranty
>period is better and is usually an indication of the quality of the
>battery.
>
>
>8. HOW DO I INSTALL A BATTERY?
>
>A car battery weights between 30 and 60 pounds, so the first question is
>do I want to install it myself? The second question is what do I do with
>the old battery if not exchanged for the new one?
>
> A. Thoroughly wash and clean the old battery, battery terminals and
>case or tray with water to minimize problems from acid or corrosion.
>Heavy corrosion can be neutralized with a mixture of baking soda and
>water. Also, mark the cables so you do not forget which one it is which
>when you reconnect.
>
> B. Remove the NEGATIVE cable first because this will minimize the
>possibility of shorting the battery when you remove the other cable.
>Next remove the POSITIVE cable and then the hold-down bracket or clamp.
>If the hold down bracket is severely corroded, replace it. Dispose the
>old battery by exchanging it when you buy your new one or by taking it to
>a recycling center. Please remember that batteries contain large amounts
>of harmful lead and acid.
>
> C. After removing the old battery, be sure that the battery tray
>and cable terminals or connectors are clean. Auto parts stores sell a
>cheap wire brush that will allow you to clean the inside of a terminal
>clamps and the terminals. If the terminals, cables or hold down brackets
>are severely corroded, replace them. Corroded terminals or cables will
>significantly reduce starting capability.
>
> D. Thinly coat the terminal and terminal clamps with a high
>temperature grease or petroleum jelly (Vaseline) to prevent corrosion.
>
> E. Place the replacement battery so that the NEGATIVE cable will
>connect to the NEGATIVE terminal. Reversing the polarity of the
>electrical system will severely damage or DESTROY it.
>
> F. After replacing the hold-down bracket, reconnect the cables in
>reverse order, i.e., attach the POSITIVE cable first and then the NEGATIVE
>cable last.
>
> G. Before starting the engine, check the electrolyte levels and
>state-of-charge. Refill or recharge as required.
>
> [If you want to retain your car's computer memory, security codes or radio
>settings, a second battery can be temporarily connected to the electrical
>system in parallel before disconnecting the first one. A cigarette
>lighter plug can used to easily connect a parallel battery.]
>
>
>9. HOW DO I RECHARGE MY BATTERY?
>
>In addition to the earlier cautions, some more words of caution:
>
> A. NEVER, NEVER disconnect a battery cable from car with the engine
>running because the battery acts like a filter for the electrical system.
>Unfiltered [pulsating DC] electricity can damage expensive electrical
>components, e.g., computer, radio, charging system, etc.
>
> B. Check the electrolyte level and be sure it is not frozen BEFORE
>recharging.
>
> C. Do NOT add water if the electrolyte is covering the top of the
>plates because during the recharging process, it will warm up and expand.
>After recharging has been completed, RECHECK the level.
>
> D. Reinstall the vent caps BEFORE recharging and recharge ONLY in
>well ventilated areas. NO smoking, sparks or open flames because while
>the battery is being recharged because they give off explosive gasses.
>
> E. If your battery is sealed, do NOT recharge with current ABOVE 25
>amps.
>
> F. Follow the charger manufacturer's procedures for connecting and
>disconnecting cables and operation to minimize the possibility of an
>explosion, but generally you should turn the charger OFF before connecting
>or disconnecting cables to a battery.
>
> G. If a battery becomes hot, or if violent gassing or spewing of
>electrolyte occurs, turn the charger off temporarily or reduce the
>charging rate.
>
> H. Insure that in car charging with an external charger will not
>damage the car's electrical system with high voltages. If this is even a
>remote possibility, then disconnect the car's negative battery cable from
>the battery BEFORE connecting the charger.
>
>Usually, a when car is jump started, it is run to recharge (or equalize)
>the battery. This might NOT fully charge it! The length of time to fully
>recharge the battery depends on the amount of discharge, the amount of
>surplus current that is diverted to the battery, how long the engine is
>run, RPM, and temperature. That is, an alternator is sized by the car
>manufacturer to carry the maximum accessory load and maintain a battery--
>NOT recharge a dead one.
>
>[For example, if 300 amps are consumed for ten seconds to start a car from
>a fully charged battery, it will take the charging system approximately
>two and one half minutes to replace the power used if 25 amps are
>available to the battery, or six minutes at ten amps, and an hour at one
>amp. Using the same example with a dead 120 minute RC battery, it would
>take approximately 86 times longer to recharge it or three and one half
>hours at 25 amps, 8.7 hours at 10 amps or 86.4 hours at one amp].
>
>If you have added lights, audio amplifiers, alarms, cellular telephones or
>other accessories, and "stop-and-go drive occurs frequently, the
>alternator might NOT produce enough current to keep your battery fully
>charged. You might need to increase the capacity of the charging system.
>[Ideally the combined load of all the lights, fans, and accessories
>should be less than 75% of the charging system's maximum output, so that
>at least 25% is available to recharge the battery.]
>
>A better method to recharge batteries is to use an external constant
>current charger which is set not to deliver more than 12% of the RC rating
>of the battery and monitor the state-of-charge. For fully discharged
>batteries, the following table, published by BCI, lists the recommended
>battery charging rates and times:
>
> Reserve Capacity Slow Charge Fast Charge
> (RC) Rating
>
> 80 Minutes or less 15 Hours @ 3 amps 2.5 Hours @ 20 amps
>
> 80 to 125 Minutes 21 Hours @ 4 amps 3.75 Hours @ 20 amps
>
> 125 to 170 Minutes 22 Hours @ 5 amps 5 Hours @ 20 amps
>
> 170 to 250 Minutes 23 Hours @ 6 amps 7.5 Hours @ 20 amps
>
> Above 250 Minutes 24 Hours @ 10 amps 6 Hours @ 40 amps
>
>The BEST method is to SLOWLY recharge it using an external constant
>voltage (or tapered current charger) because the electrolyte has more time
>to penetrate the plates. A constant voltage "automatic" charger applies
>regulated voltage at approximately 14.4 volts. A 10 amp automatic charger
>will cost between $30 and $60 U.S. at an auto parts store. [To prevent
>damage to a fully discharged battery, the current should be less than 1%
>of the CCA rating during the first 30 minutes.] With a taper charger, a
>high current, up to 30 amps, can be applied to non-sealed batteries for a
>short period up to 30 minutes maximum and then is regulated downward until
>the charge state reaches 100%.
>
>[An excellent automatic constant voltage battery charger is a 15 volt
>regulated power supply adjusted to 14.4 volts at 80 degrees F (26.7
>degrees C). If 32 degrees F (0 degrees C), then increase the charging
>voltage to 15.3 volts. When charging a maintenance free battery, add .2
>volts.]
>
>If left unattended, a cheap, unregulated trickle battery chargers can
>overcharge your battery because they can "boil off" the electrolyte. Do
>NOT use fast, high rate, or boost chargers on any battery that is sulfated
>or deeply discharged. This condition requires a constant current from one
>to two amps for 60 to 120 hours. The electrolyte should NEVER bubble
>violently while recharging because high currents only create heat and
>excess explosive gasses.
>
>
>10. WHAT IS PARASITIC LOAD?
>
>Parasitic (key off) is the cumulative load produced by electrical devices,
>e.g., clocks, computers, alarms, etc., that operate after the engine is
>stopped. Parasitic loads typically run 20 to 120 milliamps. To test the
>parasitic load an amp meter must be inserted in series with either the
>positive or negative battery terminal and it's cable without the engine
>running. If the parasitic load is prematurely discharging your battery,
>start removing fuses one-at-a-time until the offending electrical
>component is identified. Leaving your headlights on will generally
>discharge a fully charged battery (with 90 minutes of RC) in four to six
>hours.
>
>
>11. CAN I INCREASE THE LIFE OF MY BATTERY?
>
> A. Keeping your battery and engine well maintained is the BEST way
>to extend the life of your battery.
>
>For cold climates, keeping the battery fully charged and the engine warm
>will help increase the life of the battery. In the warmer climates and
>during the summer, the electrolyte levels need to be checked more
>frequently and DISTILLED water added, if required. This is due to the
>high underhood temperatures. In a study conducted by the Society of
>Automotive Engineers (SAE), the underhood temperature have increased 30%
>since 1985. Heat shields are becoming more popular and are being used by
>a number of car manufacturers to protect the batteries from the high
>underhood temperatures. Some battery manufacturers build "hot climate"
>versions by increasing the amount of electrolyte in the battery to provide
>more "cooling" or by special plate formulations. Batteries last
>approximately two thirds as long in hot climates as cold ones.
>
> B. Add distilled water--NEVER add acid or tap water and DO NOT
>OVERFILL.
>
> C. Turning off unnecessary accessories and lights BEFORE starting
>your car will decrease the load on the battery while cranking, especially
>when it is cold.
>
> D. Leaving your lights or other accessories on and fully
>discharging the battery can ruin your car battery, especially if it is
>maintenance free. If this should this occur, you should test the battery
>AFTER it has been fully recharged to determine if there is any latent or
>permanent damage.
>
> E. Reduce the parasitic (key-off) load to 120 milliamps or less.
>
> F. Storing batteries in cool locations and periodically recharging
>them.
>
> G. In cold climates, increasing the diameter (smaller wire gauge) of
>the battery cables will increase the power available to the starter motor.
>
>
>12. WHAT ARE THE MOST COMMON CAUSES OF PREMATURE BATTERY FAILURES?
>
> A. Loss of electrolyte (which account for over 50% of the failures)
>due to underhood heat or overcharging,
>
> B. Deep discharges (leaving your lights on),
>
> C. Misapplication or using an undersized battery,
>
> D. Undercharging or loose alternator belt,
>
> E. Excessive vibration (due to a loose holdown clamp),
>
> F. Using tap water,
>
> G. Corrosion, and
>
> H. Freezing.
>
>
>13. WHAT ARE SOME OF THE MYTHS ABOUT BATTERIES?
>
> A. Storing a battery on a concrete floor will discharge them.
>
>Modern lead acid battery cases are better sealed, so external leakage
>causing discharge is no longer a problem. [Temperature stratification
>within large batteries can accelerate the internal "leakage" or self
>discharge if the battery is sitting on an extremely cold floor in a warm
>room or installed in a submarine.]
>
> B. Driving a car will fully recharge a battery.
>
>There are a number of factors affecting alternator's ability to charge
>a battery. The greatest factors are how much current from the alternator
>is diverted to the battery to charge it, how long the current is available
>and temperature. Generally, running the engine at idle or short
>"stop-and go trips" during bad weather at night will not recharge the
>battery.
>
> C. A battery will not explode.
>
>While spark retarding vent caps help, recharging, a battery produces
>hydrogen and oxygen gasses. If a spark occurs, an explosion can occur.
>Remember the "Hindenburg"!
>
> D. A battery will not lose it's charge sitting in storage.
>
>A battery has self discharge or internal electrochemical "leakage" that
>will cause it to become fully discharged and sulfated over time. Prior to
>storing a battery, it should be fully charged, placed in a cool location
>above freezing, and recharged when it reaches the 50% state-of-charge
>level or once every six months, whichever occurs first. If left in a car
>or RV, disconnect the negative cable.
>
> E. Maintenance free batteries never requires electrolyte.
>
>In hot climates, the electrolyte could be "boiled off" due to the high
>underhood temperatures . Electrolyte could also be lost due to excessive
>charging voltage or charging currents.
>
> F. Test the alternator by disconnecting the battery with the engine
>running.
>
>A battery as like a voltage stabilizer or filter to the pulsating DC
>produced by the alternator. Disconnecting a battery while the engine is
>running can destroy the electronic components, e.g., computers, radio,
>stereo, alarm system, etc., or the charging system. Just say NO! if
>anyone suggests this.
>
>
>14. WHERE CAN I FIND MORE INFO ON BATTERIES?
>
>AC Delco Counterman Training Program, www.apaa.org/delco/internet.html.
>
>AC Delco Home Page, www.apaa.org/delco.
>
>"Auto Batteries", Consumer Reports, October, 1991.
>
>"Automotive Battery FAQ", Exide Batteries, http://204.170.84.25/power
> /autofaq.htm.
>
>"Automotive Electrical Troubleshooting Manual", Interstate Batteries,
> Dallas.
>
>"Batteries", Consumer Reports, February, 1987.
>
>"Battery Replacement Data Book", Battery Council International, Chicago,
> 1996.
>
>"Battery Service Manual", Battery Council International, Chicago.
>
>"Battery Training Guide", Exide, Reading, PA.
>
>"Best Bet in Auto Batteries", Consumer Reports, October, 1995.
>
>Darden, William E., "Deep Cycle Battery FAQ", http:
> //nyquist.ee.ualberta.ca/~schmaus/dcbat.html.
>
>Electrochemical Science and Technology Information Resource Home Page,
www.cmt.anl.gov/estir/info.htm.
>
>Exide Battery Home Page, 205.170.84.25/power/exidepg5.htm.
>
>"First Aid for an Auto Battery", Consumer Reports, November, 1995.
>
>Hawkins, Tim, "Batteries: Playing Pinball with Atoms", Nuts & Volts
> Magazine, November, 1995.
>
>Interstate Batteries Home Page, www.interstatebatteries.com.
>
>Johnson Controls Inc. Home Page, www.jci.com.
>
>Lead Acid Batteries Home Page, www.ncf.carleton.ca/~bf250/leadacid.html.
>
>Scheidler, Ralph E., "Introduction to Batteries and Charging Systems",
> Sure Power Systems, Tualatin, OR.
>
>Sci.chem.electrochem.battery, USEnet Newsgoup.
>
>
>Comments are always welcomed by Bill Darden at wdarden@mcimail.com or
>(214) 361-9566. For additional information on deep cycle batteries, the
>Deep Cycle Battery FAQ maybe found on the Web server at
>nyquist.ee.ualberta.ca/~schmaus or by requesting one via email from
>wdarden@mcimail.com.
>
> -------
>
>
| 
