Automotive Batteries 101

Table of Contents

• Common Battery Terminology
  
  • Performance Ratings
  • Battery Components


• How and Why Batteries Lose Power



• Causes of Battery Failure
  
  • Application and Installation
  • Service History
  • Battery Condition
  • Battery Age and Date Coding


• Automotive Battery Technologies
  
  • Starting versus Cycling Batteries
  • Flooded (Wet) batteries
  • Absorbed Glass Mat (AGM) batteries
  • Gelled Electrolyte batteries
  • VRLA (Valve Regulated Lead-Acid) Battery Applications


• Safe Handling of Batteries

Common Battery Terminology

Performance Ratings

Cold Cranking Amps (CCA):		The current a new, fully charged battery can deliver at 0°F (-17.8°C) for 30 seconds, while maintaining at least 1.2 volts per cell.
Marine Cranking Amps (MCA) or Cranking Amps (CA):		The current a new, fully charged battery can deliver at 32°F (0°C) for 30 seconds, while maintaining at least 1.2 volts per cell.
Japanese Industrial Standard (JIS)		Rating system used for most batteries produced in Japan. Commonly found in Japanese import vehicles.
Deutsche Industrie Normen (DIN)		Rating standard used by German automobile and battery companies.
Europäische Norm (EN)		Common rating standard for Europe. East Penn’s line of exact fit batteries for European vehicles follows this standard.
Reserve Capacity (RC):		The time in minutes that a new fully charged battery can deliver 25 amps at 80°F (26.7°C) at a voltage greater than or equal to 1.75 volts per cell.
Nominal Voltage:		A lead-acid cell has a nominal voltage of 2.0 volts. This is approximately the average voltage during a long, complete discharge. A typical vehicle’s electrical system is 6 volts, 12 volts or 24 volts nominal, requiring a battery pack of the same rating.
Capacity (Cn where n is time, usually in hours):		The quantity of charge in ampere hours (Ah) that a new fully charged battery can deliver in a specific period (often 20 hours) at a specific temperature (often 80°F) at a voltage greater than or equal to a specific value (often 1.75 volts per cell). Example: a battery which delivers a current of 5 amperes for 20 hours has a 20-hour capacity of 100 ampere-hours. (5A x 20h = 100Ah)

Battery Components

Group Size:		A standard battery configuration meeting certain physical size limits and other requirements, including terminal types and locations. In theory, a battery of the correct group size will fit a given vehicle regardless of the manufacturer of the battery.
Case and Cover:		The outside structure containing the battery’s parts. These are usually made from plastic (polypropylene), although some types are still made from hard rubber. Covers are generally heat sealed to the case.
Posts:		(Also called terminals or connectors.) The external connection that allows the battery to be joined to the vehicle’s electrical system. For automotive batteries, these are either top post where battery cables clamp on, or side post where battery cables bolt on.
Vents:		Apertures where gasses can escape from the battery. They may be part of the caps or part of the cover. Lead-acid batteries produce hydrogen gas, which is flammable above a certain threshold.
Grids:		The heart of the battery because they are the supporting framework for the active material (paste) of the plates. Battery grids are made of lead alloyed with other metals to give them desirable properties such as strength, low electrical resistance, low gassing rates and low corrosion rates in a hot acidic environment.
Plates:		Grids to which paste (see below) has been applied. The plates are “formed” (electrically converted to active materials) later in the process. Formed positive active material is black. It is lead dioxide. Formed negative active material is gray spongy lead.
Paste:		A thick mud-like mixture of lead oxides, sulfuric acid, water and other ingredients like reinforcing fibre. It is applied to grids to make plates. “Expander” containing barium sulfate and carbon black is added only to the negative material. Curing temperatures and humidity promote reactions that result in hardened crystals with desirable nanostructure. Cured positive plates are light orange in colour. Cured negative plates are gray due primarily to the carbon black used in the expander.
Separators:		Thin sheets of electrically insulating porous material used as spacers between the plates to prevent electrical contact between the plates while allowing the free movement of ions between the plates. Leaf separators are individual sheets sandwiched between the plates. Envelope separators are folded around the plates of one polarity or the other and sealed at the sides. East Penn automotive batteries use envelope separators made from polyethylene.
Cells:		The basic electrochemical current producing unit in a battery, consisting of an element (see below), electrolyte and casing. Each cell is approximately 2.1 volts (fully charged), therefore, a 12 volt battery has six series–connected cells. A 6 volt battery has three series–connected cells.
Element:		An assembly alternating positive and negative plates with separators between them where all of the negative plates are electrically connected in parallel and all of the positive plates are electrically connected in parallel, plus the structures necessary for making connections to the next cell or external terminal. Any number of plates can be used in an element, depending on the desired performance.
Inter-Cell Connectors:		The series electrical connections between the elements in adjacent cells. East Penn automotive batteries are connected by welds made through holes punched in cell walls.
Terminal Lug:		Structures in the first and last cells of a battery that allow a connection to external terminals. (One positive, one negative.)
Terminal Designs:		SAE post terminals – Are tapered terminal posts built to SAE standards so that all cable clamps will fit any battery with these posts. Side terminals – Are molded into the side wall near the top edge, and battery cables attach to the terminal by a bolt with threads into the terminal. L terminals – Used extensively on special application batteries for lawn & garden equipment, snowmobiles and light duty vehicles. Stud terminals – Threaded terminals typically used on heavy duty batteries.

The complete battery assembly is illustrated below.





How and Why Batteries Lose Power

A battery will lose power temporarily as it is discharged. This can be reversed. Recharging restores this power. Permanent power loss results from the effects of slow degradation of the battery components over time. This can not be reversed. Eventually, the battery will need to be replaced.

• Parasitic draws — Small loads that are used to power electrical devices such as digital clocks and electronic control modules when the ignition is off.
• Inactivity and storage — The longer a battery sits the more it will become discharged. The ground cables should be disconnected if the battery is going to be unused for over 30 days.
• Incorrect storage — The battery should always be stored upright to prevent electrolyte from escaping.
• Temperature — Higher temperatures accelerate aging and self-discharge. Lower temperatures slow aging and self-discharge, but the battery delivers less starting power when cold.
• Customer driving habits — Short trips may prevent the battery from being fully recharged, which can damage the battery over the long term. Vehicles such as taxis that sit idling for long periods can generate enough engine heat to damage the battery.

Causes of Battery Failure

Factors important in determining the cause of failure are application, installation, electrical service history and physical stress.

Proper Application and Installation

1. Is the battery being used in the application for which it was designed? A standard automotive battery used in a recreation vehicle designed for a deep cycle battery is an obvious misapplication.
2. Is the battery sized properly for the application? Both the cranking performance and reserve capacity rating must meet the vehicle’s requirements.
3. Does the vehicle have excessive electrical accessories, particularly those which have been added to the vehicle? Examples of added accessories include winches, lights, amplifiers, etc. If additional accessories have been added, a battery with greater performance and/or a larger charging system may be required.
4. Is the battery firmly secured in the vehicle? Have hold downs, heat shields, or battery trays been modified? Does the battery’s BCI Group Size match the vehicle’s OE requirements or equivalent?
5. Are the battery connections clean and properly adjusted to fit the battery terminals? Have the terminals been converted from side to top terminals or vice versa? Has the battery been relocated close to high temperature sources?

Service History

1. Question the owner regarding any past problems with the battery and/or vehicle.
2. Was the vehicle’s charging system or other parts of the electrical system repaired or altered? Have lights or other loads been left on?
3. Is the vehicle driven regularly or is it often parked for extended periods?
4. Has the vehicle spent significant time in a warmer climate? High temperatures reduce battery life.
5. Has the vehicle been difficult to start for any reason? Starting problems may have placed excessive loads on the battery or may indicate an undersized battery.
6. Did the battery tray need to be washed free of corrosion or electrolyte? This may indicate overcharging or a shorted cell.

Battery Condition

An external inspection of the battery may reveal signs of the cause of failure:

1. Do the terminals show signs of being hammered, twisted or driven down into the cover?
2. Do side terminals show signs of over-tightening? Over-tightening or using bolts that are too long can cause internal damage that can’t be seen.
3. Do the container or cover show signs of stress, damage or high temperature? Does the container or cover have worn areas indicating vibration damage?
4. Are the ends of the batteries pushed out? This can indicate plate growth.
5. Are the vent caps installed properly? Do they appear to be the original vent caps? Improperly installed or missing vents can be the cause of an explosion, leakage or contamination.
6. If the vent caps are removable, check the electrolyte levels in all cells. Are they below the tops of the plates in any or all cells? Low electrolyte levels indicate overcharging.
7. Draw some of the electrolyte into a hydrometer. Is it cloudy, discoloured or contaminated with foreign material? Cloudy or discoloured electrolyte may indicate material shedding due to overcharge, deep discharging or vibration. Electrolyte contamination may be from oil or other foreign substances being added to the battery.

Battery Age and Date Coding

1. The battery’s age is important to determine if a battery has failed prematurely or has simply worn out. The newer the battery, the more likely it just needs charging. The typical expected life of a passenger car/light truck battery in Canada is 4.5-5 years.
2. The date when the battery was put into service can usually be determined by examining the label on the top of the battery. Punch-outs indicate month and year purchased for warranty purposes. If this information is not available, check with the vehicle owner to see if the original sales receipt is available. If it is the original battery, it is the same age as the vehicle. As a last resort, a letter/number code often indicates the month and year that the battery was shipped from the manufacturer. “A8” would be January of 2008.

Automotive Battery Technologies

Starting versus Cycling Batteries

There are two general classes of battery usage — starting and cycling.

Starting batteries are designed to give short bursts of high power to start an engine. These batteries have many thin plates for low internal resistance to maximize power. They are designed for shallow cycling where the battery is not drained by very much before the alternator recharges it again. They have not been designed for and will not hold up under deep discharge/recharge cycles. Deep cycling will literally tear the battery apart on the inside as the active material sheds from the plates.

Cycling batteries have been specially engineered to withstand the effects of deep discharging and recharging cycles. The plates are thicker and the higher density paste is slightly different. East Penn uses fibreglass sheets between the separators and positive plates. The glass fibre sheets hold the active materials in place to reduce shedding and slow performance decay. Preventing direct positive plate to separator contact prevents separator oxidation, which also helps maximize battery life.

Combination "dual purpose" starting/cycling batteries provide both starting and cycling power and are best for heavier starting and moderate cycling applications. The plates are thicker and the paste is dense like the cycling batteries.

Typical applications for cycling batteries include Class 8 commercial trucks with fully loaded sleepers, marine vehicles that involve heavy duty trolling, RV applications with appliances such as refrigerators, microwaves, TVs, etc., as well as wheelchair, electric vehicle and solar applications, to name a few.



Flooded (Wet) batteries

Flooded batteries are lead-acid batteries where the electrolyte (battery acid mixed with water) flows freely within the battery cell, circulating through highly porous envelope separators (usually made of polyethylene), which separate positive and negative plates. This liquid can spill and cause corrosion if tipped or punctured. Therefore, they are not air-transportable without special containers and can’t be shipped UPS or Parcel Post or used near sensitive electronic equipment. They can only be installed "upright".

Flooded batteries lose capacity and become permanently damaged if left in a discharged condition for an extended length of time (due to sulfation) and/or are continually over discharged (due to active material shedding – particularly so for automotive starting types).



Absorbed Glass Mat (AGM) batteries

With absorbed glass mat batteries, the battery acid is "absorbed" into fibreglass separators (a sponge-like mat of fine glass fibres) so that the battery has no free-flowing electrolyte. Therefore an AGM battery can be operated in virtually any position. (However, upside down installation is not recommended.

Some AGM batteries are considered “non-spillable” and are therefore exempt from certain air, land and sea hazardous materials shipping regulations when properly labeled and packaged. This requires that the manufacturer certify that the battery meets the requirements of the exemption.

Completely maintenance-free, this type of battery is sealed under special pressure valves and should never be opened. It uses a “recombination” reaction to prevent the escape of hydrogen and oxygen gases normally lost in a flooded lead-acid battery (particularly in deep cycle applications).

In "recombination" technology the oxygen normally produced on the positive plates of all lead-acid batteries is absorbed by the negative plate. This suppresses the production of hydrogen at the negative plate and water is produced instead, retaining the moisture within the battery. Thus it never needs watering and should never be opened, since additional oxygen from the air would “poison” the battery. In fact, opening an AGM battery will void its warranty.

The spillproof and leakproof design provides added protection against expensive vehicle and equipment damage, as well as greater rider and environmental safety. The tight pack construction provides greater resistance to shock and vibration, making this type of battery excellent for off-road applications. East Penn offers a premium power sports battery in AGM format for motorcycle, ATV, snowmobile and water sport applications, all of which are subject to severe shock and vibration, as well as rider and environmental safety hazards.

While most automotive batteries are conventional flooded, there are a few vehicles (i.e. Mazda Miata) where the original equipment battery installed by the manufacturer is AGM format. East Penn also offers an AGM replacement battery (Intimidator brand) as a higher end battery for heavy accessory vehicles and/or vehicles where batteries are located outside the engine compartment (i.e. underneath seats and inside trunks) or close to sensitive electronic equipment.

AGM batteries have lower internal resistance than similar flooded batteries, which means they will provide both faster high performance starts and faster recharge times.

The “acid-starved” condition of AGM batteries protects the plates during deep discharges. AGM batteries typically last significantly longer than flooded starting batteries and excel for high current, high power applications and in extremely cold environments. They self-discharge at a lower rate than conventional batteries, making them ideal for seasonal applications where the battery is stored for part of the year.



Gelled Electrolyte batteries

A gelled electrolyte or "gel" battery is also sealed using special pressure valves and should never be opened. It is thus completely maintenance-free, much like an AGM battery and can be operated in any position (although upside down is not recommended). But where an AGM battery uses glass mat fibres to trap the electrolyte, gel batteries use a thixotropic gel.

Like the AGM battery, a recombination reaction prevents the escape of hydrogen and oxygen gasses, making the battery safe to use around expensive or sensitive electronic equipment.

Like the AGM battery, the battery may be declared “non-spillable” and be exempted from certain air, land and sea shipping regulations when properly packaged and labeled. Like the AGM battery, this requires that the manufacturer to certify that the design meets certain test requirements.

The gel inside a gelled electrolyte battery has the appearance and consistency of petroleum jelly. The "acid-starved" condition of gel batteries protects the plates during heavy deep discharges.



VRLA (Valve Regulated Lead-Acid) Battery Applications

Both AGM and Gel battery types are also known as VRLA batteries, due to their special pressure valves and sealed designs. VRLA batteries can be substituted in virtually any flooded lead-acid battery application, as well as applications where traditional flooded batteries can’t be used.

Because of their unique features and benefits, VRLA batteries are particularly well suited for:

• Deep cycle, deep discharge applications
  • Marine trolling
  • Electric vehicles
  • Portable power
  • Personnel carriers
  • Commercial deep cycle applications
  • Electronics
  • Wheelchairs
  • Floor scrubbers
  • Marine and RV house power
  • Sailboats
  • Golf cars



• Standby and emergency backup applications
  • UPS (uninterrupted power systems)
  • Emergency lighting
  • Telephone switching
  • Computer backup
  • Village power
  • Cable TV
  • Solar power



• Unusual and demanding applications
  • Race cars
  • Off-road vehicles
  • Marine and RV starting
  • Air-transported equipment
  • Wet environments
  • Diesel and I.C.E. starting

The "acid-starved" condition of both AGM and gel batteries protects the plates during heavy deep discharges. The gel battery is especially suited for super-deep discharge applications. AGM batteries excel for high current, high power applications in extremely cold environments.

VRLA batteries will work in SLI (starting, lighting, ignition) applications as long as the vehicle’s charging voltage is regulated appropriately. Many vehicle systems are set too high for gel batteries and therefore may require adjustment to properly recharge a gel battery for best performance and life. AGM batteries excel in low temperature, high current applications such as cold weather starting.



Safe Handling of Batteries

DANGER OF EXPLODING BATTERIES

Batteries contain sulfuric acid and produce explosive mixtures of hydrogen and oxygen. Because self-discharge action generates hydrogen gas even when the battery is not in operation, make sure batteries are stored and worked on in a well-ventilated area. ALWAYS wear safety glasses and a face shield when working on or near batteries. When working with batteries:

• Always wear proper eye, face and hand protection.
• Keep all sparks, flames and cigarettes away from the battery.
• Never try to open a battery with non-removable vents.
• Keep removable vents tight and level except when servicing electrolyte.
• Make sure work area is well ventilated. Avoid breathing electrolyte mist or acid fumes.
• Never lean over battery while boosting, testing or charging.
• Remove jewellery. Exercise caution when working with metallic tools or conductors to prevent short circuits and sparks.
• High voltage applications require special precautions to avoid electrocution hazards that may vary from application to application. Consult the application owners manual, service manuals and follow all warning labels.

SAFE BATTERY INSTALLATION

To assure safe installation and proper operation, follow these installation procedures:

• Before removing old battery, note position of positive (+) terminal and negative (-) terminal. Make the cables for correct connection to new battery.
• Disconnect ground cable first (this is usually the negative cable; however, older vehicles may have a positive ground).
• Clean terminals and cable connections with a wire brush. Broken connections or frayed or cut cables should be replaced.
• Install the new battery in the same position as the old one. Be sure to secure it with the hold-down assembly.
• Make sure the terminals do not touch any metal mounting, engine or body parts.
• Connect cables tightly. Connect ground cable last to avoid sparks and explosion.

SAFE CHARGING

Never attempt to charge a battery without first reviewing the instructions for the charger being used. In addition to the charger manufacturer’s instructions, these general precautions should be followed:

• Always wear proper eye, face and hand protection.
• Always charge batteries in a well-ventilated area.
• Keep vents tight and level.
• Use an automatic voltage-controlled charger set for the correct battery type whenever possible to prevent problems if the battery cannot be monitored during charge.
• When making connections to a battery or disconnecting a battery, follow the instructions supplied with the charger with regard to (1) whether charger should be plugged in or not, (2) whether charger should be switched on or off, (3) in what order and where one should make the connections, and (4) whether charging in a vehicle is permitted and any special precautions to be followed when charging in a vehicle. Many chargers spark when turned off or turned on, whether plugged in or not. Some charger instructions demand that the user (1) add a large cable, not supplied by the charger manufacturer, to the negative terminal, and (2) make the final connection to this cable, well away from the battery.
• Never try to charge a visibly damaged battery.
• Do not attempt to charge a frozen battery. Thaw it fully before attempting to charge.
• Make sure that the charger leads to the battery are not broken, frayed or loose.
• If the battery becomes hot, or if violent gassing or spewing of electrolyte occurs, reduce the charging rate or turn off the charger temporarily.

HANDLING BATTERY ACID

Battery acid, or electrolyte, is a solution of sulfuric acid and water that can destroy clothing and burn the skin. Use extreme caution when handling electrolyte and keep an acid neutralizing solution – such as baking soda or household ammonia mixed with water – readily available. When handling batteries:

• Always wear proper eye, face and hand protection.
• If the electrolyte is splashed into an eye, immediately force the eye open and flood it with clean, cool water for at least 15 minutes. Get prompt medical attention.
• If electrolyte is taken internally, drink large quantities of water or milk. DO NOT induce vomiting. Get prompt medical attention.
• Neutralize with baking soda any electrolyte that spills on a vehicle or in the work area. After neutralizing, rinse contaminated area clean with water.
• Mixing acid can be very dangerous. Under no conditions should a consumer prepare or adjust the concentration of electrolyte using concentrated sulfuric acid.

SAFE BOOSTER CABLE OPERATION

When jump starting, always wear proper eye protection and never lean over the battery. Inspect both batteries before connecting booster cables. Do not jump start a damaged battery. Be sure vent caps are tight and level. Make certain that the vehicles are not touching and both ignition switches are turned to the “OFF” position. Refer to the vehicle owner’s manual for other specific information.

1. Connect positive (+) booster cable to positive (+) terminal of discharged battery.
2. Connect other end of positive (+) cable to positive (+) terminal of assisting battery.
3. Connect negative (-) cable to negative (-) terminal of assisting battery.
4. MAKE FINAL CONNECTION OF NEGATIVE (-) CABLE TO ENGINE BLOCK OF STALLED VEHICLE, AWAY FROM BATTERY AND FUEL SYSTEM.
5. Start vehicle and remove cable in REVERSE order of connections.