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Car Battery How does a battery work? What should you look for in a car battery? Here are further guidelines.

Why won't my engine start?

Battery Details Battery Life Battery Testing Battery Usage Rechargeable Batteries Non-Rechargeable Batteries

What is a Battery? Where are batteries used? What are the types of batteries? What materials are required to manufacture a battery? How is a battery made? What is the external case of a battery made of, high-density tough polypropylene or hard rubber? How do you determine the dimensions of the external case of a battery? What type of material is it? Why doesn't it get damaged by an electrolyte or current? What types of materials are used in a battery? Where is lead used in a battery? Where is lithium used in a battery? What others materials can be used in their place? How are lead and lithium extracted? What are battery plates? How are plates of a battery made? Why do we need them? What type of electrolyte is in a battery? What should be the electrolyte level in a battery? How does a battery work? How do batteries die? Why are vehicles negatively grounded? How do you do capacity testing of a battery? What is a state-of-charge and how do you do it? What is a battery hydrometer? What are the uses of a battery hydrometer? How do you use a battery hydrometer? What is a low electrolyte level? How and when can a battery explode on its own? What precautions should one use while handling a battery? What type of cables should one use for a battery? What is an alternator belt? What should you look for and ask during inspection? When should you refill electrolytes? When should you recharge a battery? Why use Lithium batteries? Why use Rechargeable Lithium Ion batteries? Why use Rechargeable NiCd batteries? Why use Rechargeable NiMH batteries? Why use alkaline batteries? Why use Zinc Air batteries? Why use Silver Oxide batteries? Why use heavy duty batteries? What is an Ampere? What is mAh? What is Ah? What is Cut off voltage? What does OEM mean? What is a Cycle? What is a Deep Cycle battery? Why use an AGM battery? What is MCA? What is CCA? What is PCA? What is a Volt? What is a Watt? What is an OHM? What is RC? What is a Starting battery? What is sulfation of batteries? Why use Gel batteries? What is a "smart" and "dumb" battery? What is self-discharge? What is Shelf life? What is a Capacity and why should I care? How do I select a charger for my SLA battery? How do I find the right battery for my cell phone? How do I connect batteries in series? How do I jump start my battery using booster cables? How do I connect batteries in parallel? What do I do if I cant find the battery I am looking for? Can you build custom batteries? Performance How long should a rechargeable last? Does it help to store batteries in refrigerator? My new battery isn't charging is it defective? What is the battery standby and talk time? Do batteries self discharge not in use? Do I ever need to add acid to my battery? Can batteries freeze? I just received my new battery. Why isn't it working? Will my device's performance differ if I use your aftermarket battery? How can I maximize performance? Is it possible to upgrade the battery in my device to a newer chemistry? Can I overcharge a battery? Disposal/Recycling How do I dispose of batteries? Are lead acid batteries recycleable?

,td> What is a Battery?

A battery is an electric storage device, which can be found in any number of shapes, sizes, voltages and capacities. When two conducting materials (often-dissimilar metals) are immersed in a solution, an electrical potential will exist between them. If connected together through a closed circuit, a current will flow.

The value of this potential (or voltage) is dependent on the materials used, giving rise to a whole family or battery types each having benefits and restrictions in use. Examples are: lead acid, nickel-cadmium, lithium, silver alkaline. A battery is simply an arrangement where a number of cells are connected together with a given voltage and capacity. The more the number of cells higher is the voltage, and larger the plates the larger is the capacity. Purely for convenience, batteries are made in 12 volt blocks with 6 cells, but are also available in 6 volt, 4 volt and even 2 volt single cell blocks.

A battery is an electrochemical cell (or enclosed and protected material) that can be charged electrically to provide a static potential for power or released electrical charge when needed.

A battery generally consists of an anode, a cathode, and an electrolyte.

Common types of commercial batteries and some of their characteristics and advantages are summarized in the following table. Battery types not shown include the Zinc-Air, Flooded Lead Acid, and Alkaline batteries.

Battery Type Characteristics Typical Uses Advantages
Sealed Lead Acid (SLA) battery Can hold a charge for up to 3 years Backup emergency power source Inexpensive

Nickel-Cadmium (Ni-Cd) battery Fast, even energy discharge Appliances, audio and video equipment, toys; most popular batter Relatively inexpensive; widely available

Nickel-Metal Hydride (Ni-MH) battery Typical power capacity i1.2 V - 1200 to 1500 mAh; extended life 2300 mAh; 2.5 to 4 hours battery life Portable computers; cellular phones; same as for Ni-Cd batteries No memory effect; unused capacity remains usable

Lithium Ion (Li-Ion) battery Stable and safe; highest energy capacity Portable computers; cellular phones; same as for Ni-Cd batteries Twice the charge capacity of Ni-Cd; slow self-discharge

Before you use your Rechargeable Batteries.

Always refer to any charging directions that are provided with your battery for specific charging instructions as most rechargeable batteries will require an activation charge prior to use. Rechargeable battery types include those with the following chemistries; Nickel Cadmium (NiCd), Nickel Metal Hydride (NiMH), Lithium Ion (Li Ion) and Sealed Lead Acid (SLA) variations (AGM, Gel). Prior to use or charging, be sure to remove any protective guards or covers. Many chargers have light displays that will indicate full charge status, however will continue to provide a charge to the battery. For NiCd, NiMH and Li Ion batteries, we recommend an activating charge or 12-24 hours prior to first use. For SLA batteries, which ship in close to full state of charge, we recommend a slight boost charge for 2-4 hours with a charger appropriate to the amperage of the battery (see How to Select a Charger for SLA for more details). For all batteries, full runtime may take up to 4-charge/discharge cycles.

Before you use your Non-Rechargeable Batteries.

Non-rechargeable battery types include those with the following chemistries; Alkaline, Heavy Duty, Lithium, Silver Oxide, Zinc Air, Carbon Zinc and Nickel Oxy Hydroxide. These battery types are ready to power your device out of the package and should never be placed in a charger. Be sure to remove any protective guards or covers prior to use.

Why use Lithium batteries?

Lithium is a very active material that provides a great deal of power relative to the amount of material used in the battery. Lithium batteries are extremely light in weight while maintaining a higher voltage and longer service life compared to other primary chemistries such as alkaline. Non-rechargeable lithium batteries are typically 3.0V to 3.6V in range, but 1.5V AA and AAA formats are also available.

Why use Rechargeable Lithium Ion batteries?

Li-ion (lithium ion) batteries use lithium compounds which are much more stable than the elemental lithium used in non rechargeable lithium batteries. A lithium battery should never be recharged while lithium-ion batteries are designed to be recharged hundreds of times. Rechargeable Lithium Ion batteries have a higher energy density than most other types of rechargeables. This means that for their size or weight they can store more energy than other rechargeable batteries. They also operate at higher voltages than other rechargeables, typically about 3.7 volts for lithium-ion vs. 1.2 volts for NiMH or NiCd. This means a single cell can often be used rather than multiple NiMH or NiCd cells. Lithium-ion batteries also have a lower self discharge rate than other types of rechargeable batteries. This means that once they are charged they will retain their charge for a longer time than other types of rechargeable batteries. NiMH and NiCd batteries can lose anywhere from 1-5% of their charge per day, (depending on the storage temperature) even if they are not installed in a device. Lithium-ion batteries will retain most of their charge even after months of storage.

Why use Rechargeable NiCd batteries?

NiCd (NiCad or Nickel Cadmium) batteries provide high discharge capability with great cycling performance. Generally utilized in every day use applications such as cordless phone or in high drain, fast recharge applications such as cordless tool or 2-way radio. NiCd batteries offer more cycling capabilty than NiMH, but with lower capacity. All NiCd batteries must be recycled.

Why use Rechargeable NiMH batteries?

NiMH (Nickel Metal Hydride) batteries provide outstanding capacity in a lightweight, rechargeable format. NiMH is interchangeable with NiCd in devices while providing a more environmentally friendly profile. Generally utilized in applications ranging from cellular phone to camcorder/digital camera. NiMH batteries offer higher capacity than NiCd, but with fewer cycles. NiMH batteries should be recycled.

Why use alkaline batteries?

Alkaline batteries, also known as manganese dioxide, are non-rechargeable and are the most commonly used batteries for heavy current, extended run-time disposable applications. Able to operate in a wide range of temperatures and perform under varying drains (low and high), alkaline batteries are the choice for consumer electronics. The most common sizes are AA, AAA, C, D and 9V configurations.

Why use Zinc Air batteries?

Zinc Air batteries provide the highest power density for non-rechargeable chemistries per unit of weight. Compact in size and utilizing oxygen for "activation", zinc air batteries are commonly used in hearing aid, medical and mercury replacement applications.

Why use Silver Oxide batteries?

Silver Oxide batteries provide extensive power in miniature configurations. Primary applications for silver oxide batteries are watches, cameras and measurement instruments.

Why use heavy duty batteries?

Heavy Duty non-rechargeable batteries, also recognized as carbon zinc or zinc chloride, provide dependable, economic power solutions for every day use. Generally used in low drain, consumer electronics, heavy duty batteries are configured in the most common sizes (AA, AAA, C, D, 9V), as well as, specialty sizes for telecommunications, hobby and industrial uses.

What is an Ampere?

The amount of current flow within a circuit. Measured in Amps.

What is mAh?

mAh (milli-ampere hour) is a capacity rating that measures how much current a battery will discharge over a specified period of time (typically a one hour period). Higher mAh ratings do not necessarily reflect how fast current can be drawn, rather, how long a current can be drawn. For example a 2000 mAh battery will sustain a 2000 milli-Amp (2 ampere) draw for approximately one hour before dropping to a voltage level that is considered discharged. A 1700 mAh battery will sustain a 1700 milli-Amp (1.7 ampere) draw for approximately one hour. Overall capacity will be influenced by other factors including temperature, depth of discharge and speed of discharge.

What is Ah?

Ah (Ampere hour) is a capacity rating that measures how much current a battery will discharge over a specified period of time (generally a 20 hour period). Higher mAh ratings do not necessarily reflect how fast current can be drawn, rather, how long a current can be drawn. For example a 20Ah battery will sustain a 1-amp draw for approximately 20 hours before dropping to a voltage level that is considered discharged. A 40Ah battery will sustain an 8-Amp draw for approximately five hours. Overall capacity will be influenced by other factors including temperature, depth of discharge and speed of charge/discharge.

What is Cut off voltage?

Recognized as the voltage at the end of a useful discharge. Cut off voltage will vary by device. However, the cut off voltage for a device specifies the inoperable point for the device utilizing battery power.

What does OEM mean?

OEM stands for Original Equipment Manufacturer, referring to the particular maker of the battery. OEM batteries are often referred to as "original" batteries.

What is a Cycle?

A cycle is considered one discharge and one charge sequence for a rechargeable battery.

What is a Deep Cycle battery?

Deep cycle batteries are designed for multiple, extended discharge/charge cycles. Deep cycle batteries can be discharged as much as 80% time after time and fully recover. This term generally refers to lead-based batteries designed with thicker lead plates than a standard automotive battery. Deep Cycle batteries provide outstanding performance in marine, RV, wheelchair/mobility and security applications.

Why use an AGM battery?

An AGM (Absorbed Glass Mat) battery is a sealed, non-spillable maintenance free, valve regulated battery. An AGM battery utilizes a fine fiber glass material seperator between the lead plates within the battery. AGM batteries, also called starved electrolyte, operate with no maintenance, can be installed in most any configuration (except inverted) without spill and provide outstanding power per dollar invested. AGM batteries are commonly interchanged with traditional flooded lead acid batteries as the charge/discharge profile of these batteries are similar. AGM batteries have low internal resistance and a very low self-discharge rate (from 1% to 3% per month). So they can sit in storage for much longer periods without charging. The AGM design is also highly resistant to vibration deterioration.

What is MCA?

MCA (marine cranking amps) is a measurement of the starting power of a battery at 32°F under a load (ampere draw) for 30 seconds with the end voltage maintained at 1.20 volts per cell. MCA is generally 20% higher than CCA (cold cranking amps).

What is CCA?

CCA (cold cranking amps) is a measurement of the starting power of a battery at 0°F under a load (ampere draw) for 30 seconds with the end voltage maintained at 1.20 volts per cell. Several variations of CCA ratings may be applied to a battery including; MCA (marine cranking amps) or CA (Cranking amps), which are generally 20% higher than CCA (cold cranking amps) and reflect higher temperature testing.

What is PCA?

PCA (Pulse Crank Amps) is a rating specifically geared towards starting applications only. PCA is a short duration (5 seconds), high rate discharge measurement generally used in the powersport industry.

What is a Volt?

A volt is the unit of measure for electrical potential or pressure.

What is a Watt?

A watt is the unit for measuring electrical power, i.e., the rate of doing work, in moving electrons by, or against, an electrical potential. Formula: Watts = Amperes x Volts.

What is an OHM?

OHM is a unit for measuring electrical resistance or impedance within an electrical circuit.

What is RC?

RC (reserve capacity) is the number of minutes that a battery can support a 25 ampere load at 80°F until its terminal voltage drops to 1.75 volts per cell or 10.50 volts for a 12V battery. For example, a 12V battery that has a reserve capacity rating of 100 minutes, signifies that it can be discharged at 25 amps for 100 minutes at 80°F before its voltage drops to 10.50 volts.

What is a Starting battery?

Starting batteries (sometimes called SLI for starting, lighting, ignition) are commonly used to start and run engines. Engine starters are generally rated for their output cranking power (CCA). Starting batteries are not recommended for deep cycle applications, but will provide some extended power (defined as reserve capacity RC) in the event of failure of a vehicles electrical generating system.

What is sulfation of batteries?

Sulfation is the formation or deposit of lead sulfate on the surface of and within the pores of the active material of the lead plates within a battery. If the sulfation becomes excessive and forms large crystals on the plates, the battery will not operate efficiently or may not work at all. Common causes of battery sulfation are standing a long time in a discharged condition, operating at excessive temperatures, and prolonged under or over charging.

Why use Gel batteries?

A gel battery design is a sealed, non-spillable maintenance free, valve regulated battery. A Gel battery has a gelling agent added to the electrolyte to reduce movement inside the battery case. Many gel batteries also use one way valves in place of open vents, this helps the normal internal gasses to recombine back into water in the battery, reducing gassing. "Gel Cell" batteries are non-spillable even if they are broken. Gel batteries are generally used in deep cycle applications and provide great deep discharge and recovery capabilities.

What is a "smart" and "dumb" battery?

Smart batteries have internal circuit boards with smart chips that allow them to communicate with laptop/computer/notebook and monitor battery performance. Dumb batteries will operate the device, but lack the communication chip.

What is self-discharge?

Self-discharge is the loss of useful capacity within a battery due to internal chemical reactions. Self- discharge will occur within all battery chemistries and will be influenced by temperature. Self-discharge will occur regardless of whether the battery is connected to a device or not.

What is Shelf life?

The amount of time a battery will retain an operable percentage of it's stated capacity (calculated under ambient temperature storage conditions).

What is Capacity and why should I care?

Capacity is the measure of the energy stored in a battery. Expressed in Ah (Ampere hour) or mAh (milli-Ampere hour), capacity defines the ability of a battery to perform under specified discharge criteria over a set period of time.

How do I select a charger for my SLA battery?

The performance and service life of a sealed lead acid (SLA) battery will be greatly impacted by the correct selection and use of a charger. Sealed lead acid batteries include AGM, VRLA and Gel types. When choosing a charger it is important to take into account the following factors; intended battery use, economic factors, recharge time, anticipated frequency and depth of discharge and expected service life. A general rule of thumb when selecting a charger for an SLA battery is use one that is no more than 20% of the capacity rating of the battery (at a 20hr. rate). For example, to charge a 12-Volt, 7.5Ah battery, you would select a charger with a maximum charge output of 1.5 Amps (7.5 x 0.20 = 1.5).

How do I find the right battery for my cell phone?

You can search for a cell phone battery by using the brand or model number of your particular phone. If you don't know your brand or model number, look at the label inside the battery compartment. Almost every cell phone has a manufacturer's label which includes the brand and model number on it. BatteriesPlus.com allows you to enter this information using our keyword search feature. If you need help finding the right battery for your phone, our customer support team is ready to assist you via email or phone. With our wide selection, you're sure to find the cell phone battery you need at a great price at BatteriesPlus.com.

How do I connect batteries in series?

Warning: Do not connect batteries of different chemistries, voltage or capacity in series. The positive terminal of the first battery is connected to the negative terminal of the second battery, the positive terminal of the second is connected to the negative of the third, etc. The voltage of the assembled battery is the sum of the battery voltages of the individual batteries. So the batteries are connected: + to - to + to - to + to -, etc. The capacity of the battery is unchanged.

How do I jump start my battery using booster cables?

Warning: Batteries produce explosive gases. These instructions are designed to minimize the explosion hazard. Keep sparks, flames and cigarettes away from batteries at all times. Both batteries should be of the same voltage (6, 12, etc.).

Safe Booster Cable Operation

When jump starting, always wear proper eye protection and never lean over the battery. Do not jump start a damaged battery; inspect both batteries before connecting booster cables. Be sure vent caps are tight and level. Be sure that the vehicles are not touching and that both ignition switches are in the "OFF" position. Turn off all electrical equipment (radio, defroster, windshield wipers, lights, etc.)

The following steps should be followed exactly:

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 CARBURETOR.
5. Be sure that cables are clear of fan blades, belts and other moving parts of both engines.
6. Start vehicle and remove cables in REVERSE order of connections.

How do I connect batteries in parallel?

Warning: Do not connect batteries of different chemistries, voltage or capacity in parallel.The positive terminal of the first battery is connected to the positive terminal of the second battery, the positive terminal of the second is connected to the positive of the third, etc. and The negative terminal of the first battery is connected to the negative terminal of the second battery, the negative terminal of the second is connected to the negative of the third, etc. So the batteries are connected: + to + to + and - to - to -. In this configuration, the capacity is the sum of the capacities of the individual batteries and voltage is unchanged.

What do I do if I cant find the battery I am looking for?

If you are looking for an item that's not listed in our references, we encourage you to call us at 1-800-677-8278 and we will directly search for a solution. As America's Battery Experts, we will get you the solution to your battery problem.

Can you build custom batteries?

Batteries Plus stores all have the capability to custom design and assemble battery packs. With 1000's of Batteries for 1000's of items, we can develop and implement a power solution to meet your needs. Please use our locator to find a store near you or contact our Battery Experts at 1-800-677-8278.

How long should a rechargable last?

The life of a battery operating under normal conditions should be between 500 to 800 charge-discharge cycles. This translates into one and a half to three years of battery life for the average user. As your rechargeable battery begins to die, you will notice a decline in the running time of the battery. When your two hour battery is only supplying you with twenty minutes worth of use, it is time for a new one. When a battery is not used for extensive periods of time it should be removed from the device and stored in a cool, dry and clean environment. Self-discharge will occur when the battery is not used for an extended time period. Fully charge the battery before use after storage. Long term storage will have permanent effects on the battery's capacity.

Does it help to store batteries in refrigerator?

Not really. Batteries should be stored in a dry location at room temperature. There is a minimal benefit to storing them at a lower temperature, but generally it is not recommended since the high humidity levels inside of the refrigerator can cause the battery cell container to rust. If you currently have batteries stored in a refrigerator, be sure to allow them to warm up to room temperature before using them in your device.

My new battery isn't charging; is it defective?

New batteries come in a slightly discharged condition and must be fully charged before use. It is recommended that you fully charge and discharge the new battery two to four times to allow it to reach its maximum rated capacity. An overnight charge (approximately twelve hours) is recommended. Note: It is normal for a battery to become warm to the touch during charging and discharging. When charging the battery for the first time, the device may indicate that charging is complete after just 10 or 15 minutes. This is a normal with rechargeable batteries. New batteries are hard for the device to charge; they have never been fully charged and not “broken in.” Sometimes the device's charger will stop charging a new battery before it is fully charged. If this happens, remove the battery from the device and then reinsert it. The charge cycle should begin again. This may happen several times during the first battery charge.

What is the battery standby and talk time?

Standby time is recognized as the time when your cell phone is on, but you are not actively talking. Talk time is defined as the run time for actual talking on your cell phone. Both stand by and talk time will vary by phone type (analog or digital), geography, strength of signal, your service provider, etc. For comparative purposes, you should review the capacity (mAh rating) for a battery. The higher the capacity for a battery for a specific phone, the longer the stand by and talk time.

Do batteries self discharge not in use?

All batteries, regardless of their chemistry, self-discharge. The rate of self-discharge depends both on the type of battery and the storage temperature the batteries are exposed to.

Do I ever need to add acid to my battery?

Under normal operating conditions, you never need to add acid or electrolyte. Low maintenance batteries may need fluid added to keep the "plates" safely immersed. For these scenarios, only distilled, deionized or approved water should be added to achieve the recommended levels. When a battery is shipped in a dry state or accidental spillage occurs, electrolyte should be added to the battery. Once filled, a battery should only need periodic water addition.

Can batteries freeze?

In a partially discharged state, the electrolyte in a lead acid battery may freeze. At a 40% state of charge, electrolyte will freeze if the temperature reaches approximately 16.0°F. The freezing temperature of the electrolyte in a fully charged battery is -92.0°F.

I just receieved my new battery, why isn't it working?

Don’t worry. There is nothing wrong with your rechargeable battery. Your rechargeable battery will arrive to you in a slightly discharged condition. Therefore, it must be charged in order for it to work. We recommend that new batteries should be charged and discharged two to four times in order to allow them to reach their capacity.

Will my device's performance differ if I use your aftermarket battery?

Due to technological advancements, replacement batters or “after market” batteries will often last longer than the original equipment manufacturer (OEM) batteries that came with your device.

How can I maximize performance?

Across all battery types, there are several things that you can do to ensure the maximum production from your battery: Always stored batteries in a cool and dry place and should be fully charged before being stored for long periods of time. Never leave your battery in its charger for more than 24 hours. Doing so will shorten the life of your battery. Keep your batteries clean. Clean dirty batteries with a cotton swab and alcohol. A clean battery will ensure a good connection between your battery and its device. Keep your batteries dry. Moisture can corrode contact points and limit charge/dischare performance.Do not leave your battery dormant.

Is it possible to upgrade the battery in my device to a newer chemistry?

NiCd, NiMH and Li-Ion are all fundamentally different technologies and cannot be substituted for one another unless the device has been pre-configured from the factory to accept more than one type of rechargeable battery. The difference between them stems from the fact that each technology requires a different charging pattern to be properly recharged. Therefore, the portable device's charger must be properly configured to handle a given type of rechargeable battery. Refer to your owners manual to find out which rechargeable battery types the particular device supports. Our cross reference information will automatically list all of the battery types supported by the machine.

Can I overcharge a battery?

Yes, overcharging batteries can reduce their effectivness, reduce the life of the battery, and may cause additional problems. Once a battery is fully charged, you should take it off the charger.

How do I dispose of batteries?

All rechargeable batteries must be disposed of properly, through approved recycling facilities. Rechargeable battery types include; NiCd, NiMH, Li Ion, and Lead Acid (Pb). Batteries Plus is associated with EPA recognized recycling facilities for proper recovery and re-use of battery components. Locate your nearest Batteries Plus store for best recycling options. Be environmentally conscious. Recycle your batteries.

Are lead acid batteries recycleable?

Yes. Lead acid batteries are the most commonly recycled product in the world! The lead in the battery is re-used in new batteries. The plastic containers and covers of old batteries are neutralized, reground and used in the manufacture of new battery cases. The electrolyte can be processed for recycled waste water uses. In some cases, the electrolyte is cleaned and reprocessed and sold as battery grade electrolyte. In other instances, the sulfate content is removed as Ammonia Sulfate and used in fertilizers. The separators are often used as a fuel source for the recycling process.

Question: What are the advantages of a lithium-ion battery?

Answer: Lithium-ion batteries are the latest technology for portable use. These batteries do not suffer from the memory effect. Compared with a Ni-Cd battery, these batteries will deliver twice the runtime on each charge. It is available only in a limited number of sizes and models. They have a life expectancy of 300-400 charge/discharge cycles. Generally, lithium batteries are designed to be recharged in the device rather than in an external charger.

Question: Can I use an alkaline battery to replace a manganese battery?

Answer: No.

Battery Life

Question: Is there a formula to determine battery life in a given application?

Answer: Yes; however, it is a formula for a ballpark estimate only and cannot be used to calculate battery life for alkalines. You must to have the current drain of the device and mAh rating of the battery to make this calculation.

Estimated total battery life = (Ib / Id) x 0.7

Where:
Ib = Total Capacity Rating of battery (mAh)
Id = Current Consumption of the device in milliamps (mA)

Note: Use of this formula does not guarantee that you will get the determined battery life. Other factors such as weather condition (temperature, humidity, etc.), and battery condition can extend/shorten the battery life.

Battery Testing

When testing my battery with a multimeter, why do I get a low voltage reading?

Multimeter Battery TestAnswer: Batteries do not show their correct voltage unless under a load. Battery testers are designed to provide this load; however, when testing batteries with a multimeter, you must have the meter set to measure DC voltage and place the battery under load by using a resistor in parallel with the test leads of the meter (see illustration at right). If the voltage reads the same on a multimeter with the resistor or without, then the battery is either low or dead and should be replaced.

Battery Usage

Why does my manual say I should not leave the batteries installed?

Answer: Leaving batteries in a battery compartment for long periods (a week or more) without being used can cause even leak-proof batteries to leak eventually. While two or three days should not be a problem, if the device will be not be used for a week or longer, we recommend that the batteries be removed.

Brian Kimberlin, Director of North American Battery Business Unit for Panasonic has graciously helped to compile answers to these frequently asked questions:

Q. What is the average shelf life of batteries?

A. Average shelf life is generally 7 years for alkaline batteries. Shelf life can vary according to battery composition.

Q. Does the quality of the battery affect product operation or only duration? In other words, is the flashlight beam strength affected or does quality only affect how long the batteries will last?

A. The quality of the battery affects both operation and duration. As an example, flashlight performance will be better and it will last longer if you use better quality batteries. Using quality batteries can also reduce the risk of leakage in consumer goods. Quality of the battery is very important and consumers should feel confident in the battery brands they purchase.

Q. How does cold weather affect batteries?

A. Cold weather does not generally affect battery performance. In fact certain batteries such as lithium batteries actually do better in extreme temperatures.

Q. How does hot weather affect batteries?

A. Hot temperatures are not recommended for batteries. Therefore flashlights, cameras and other battery-operated products should not be left in a vehicle in hot climates.

Q. Should batteries be stored in the refrigerator as our parents and grandparents used to do?

A. This is not recommended for today’s batteries.

Q. What is the difference between alkaline and non-alkaline batteries?

A. Alkaline and non-alkaline batteries have different compositions and vary in performance.

Alkaline batteries are widely used in consumer electronics and appliances. Panasonic’s Digital Power is the top performer in high tech electronics and appliances.

Two examples of non-alkaline batteries would be Panasonic Super Heavy Duty batteries recommended for low drain consumer goods such as radios and flashlights, and Panasonic Oxyride Extreme Power Batteries that are recommended for high drain electronics such as MP3 players and digital still cameras.

Batteries are all over the place -- in our cars, our PCs, laptops, portable MP3 players and cell phones. A battery is essentially a can full of chemicals that produce electrons. Chemical reactions that produce electrons are called electrochemical reactions.

If you look at any battery, you'll notice that it has two terminals. One terminal is marked (+), or positive, while the other is marked (-), or negative. In an AA, C or D cell (normal flashlight batteries), the ends of the battery are the terminals. In a large car battery, there are two heavy lead posts that act as the terminals.

Electrons collect on the negative terminal of the battery. If you connect a wire between the negative and positive terminals, the electrons will flow from the negative to the positive terminal as fast as they can (and wear out the battery very quickly -- this also tends to be dangerous, especially with large batteries, so it is not something you want to be doing). Normally, you connect some type of load to the battery using the wire. The load might be something like a light bulb, a motor or an electronic circuit like a radio.

More on Batteries

Inside the battery itself, a chemical reaction produces the electrons. The speed of electron production by this chemical reaction (the battery's internal resistance) controls how many electrons can flow between the terminals. Electrons flow from the battery into a wire, and must travel from the negative to the positive terminal for the chemical reaction to take place. That is why a battery can sit on a shelf for a year and still have plenty of power -- unless electrons are flowing from the negative to the positive terminal, the chemical reaction does not take place. Once you connect a wire, the reaction starts. The ability to harness this sort of reaction started with the voltaic pile.

basic configuration

Next, we'll check out how a voltaic pile works and look at other types of batteries.

Battery History

The first battery was created by Alessandro Volta in 1800. To create his battery, he made a stack by alternating layers of zinc, blotting paper soaked in salt water, and silver. This arrangement was known as a voltaic pile. The top and bottom layers of the pile must be different metals. If you attach a wire to the top and bottom of the pile, you can measure a voltage and a current from the pile. The pile can be stacked as high as you like, and each layer will increase the voltage by a fixed amount.

voltaic pile
A voltaic pile

In the 1800s, before the invention of the electrical generator (the generator was not invented and perfected until the 1870s), the Daniell cell was extremely common for operating telegraphs and doorbells. The Daniell cell is also known by three other names:

Crowfoot cell (because of the typical shape of the zinc electrode)
Gravity cell (because gravity keeps the two sulfates separated)
Wet cell (because it uses liquids for the electrolytes, as opposed to the modern dry cell)

The Daniell cell is a wet cell consisting of copper and zinc plates and copper and zinc sulfates. To make the Daniell cell, the copper plate is placed at the bottom of a glass jar. Copper sulfate solution is poured over the plate to half-fill the jar. Then a zinc plate is hung in the jar and a zinc sulfate solution is poured very carefully into the jar. Copper sulfate is denser than zinc sulfate, so the zinc sulfate "floats" on top of the copper sulfate. Obviously, this arrangement does not work very well in a flashlight, but it works fine for stationary applications.

daniell cell
The Daniell Cell
If you have access to zinc sulfate and copper sulfate, you can try making your own Daniell cell. In the next section, we'll show you how to do it.

Battery Experiments: Voltaic Pile

If you want to learn about the electrochemical reactions used to create batteries, it is easy to do experiments at home to try out different combinations. To do these experiments accurately, you will want to purchase an inexpensive ($10 to $20) volt-ohm meter at the local electronics or hardware store. Make sure that the meter can read low voltages (in the 1-volt range) and low currents (in the 5- to 10-milliamp range). This way, you will be able to see exactly what your battery is doing.

You can create your own voltaic pile using coins and paper towels. Mix salt with water (as much salt as the water will hold) and soak the paper towel in this brine. Then create a pile by alternating pennies and nickels. See what kind of voltage and current the pile produces. Try a different number of layers and see what effect it has on voltage. Then try alternating pennies and dimes and see what happens. Also try dimes and nickels. Other metals to try include aluminum foil and steel. Each metallic combination should produce a slightly different voltage.

Another simple experiment you can try involves a baby food jar (if you don't have a baby around the house, just purchase a few jars of baby food at the market and empty them out), a dilute acid, wire and nails. Fill the jar with lemon juice or vinegar (dilute acids) and place a nail and a piece of copper wire in the jar so that they are not touching. Try zinc-coated (galvanized) nails and plain iron nails. Then measure the voltage and current by attaching your volt meter to the two pieces of metal. Replace the lemon juice with salt water, and try different coins and metals as well to see the effect on voltage and current.

Probably the simplest battery you can create is called a zinc/carbon battery. By understanding the chemical reaction going on inside this battery, you can understand how batteries work in general.

Imagine that you have a jar of sulfuric acid (H2SO4). Stick a zinc rod in it, and the acid will immediately start to eat away at the zinc. You will see hydrogen gas bubbles forming on the zinc, and the rod and acid will start to heat up. Here's what is happening:

The acid molecules break up into three ions: two H+ (hydrogen) ions and one SO4-- (sulfate) ion.
The zinc atoms on the surface of the zinc rod lose two electrons (2e-) to become Zn++ ions.
The Zn++ ions combine with the SO4-- ion to create ZnSO4 (zinc sulfate), which dissolves in the acid.
The electrons from the zinc atoms combine with the hydrogen ions in the acid to create H2 molecules (hydrogen gas). We see the hydrogen gas as bubbles forming on the zinc rod.

If you now stick a carbon rod in the acid, the acid does nothing to it. But if you connect a wire between the zinc rod and the carbon rod, two things change:

The electrons flow through the wire and combine with hydrogen on the carbon rod, so hydrogen gas begins bubbling off the carbon rod.
There is less heat. You can power a light bulb or similar load using the electrons flowing through the wire, and you can measure a voltage and current in the wire. Some of the heat energy is turned into electron motion.

The electrons go to the trouble to move to the carbon rod because they find it easier to combine with hydrogen there. There is a characteristic voltage in the cell of 0.76 volts. Eventually, the zinc rod dissolves completely or the hydrogen ions in the acid get used up and the battery "dies."

In the next section, we'll look at exactly what is happening with the battery's chemistry.

Battery Reactions and Chemistry

In any battery, an electrochemical reaction occurs like the ones described on the previous page. This reaction moves electrons from one pole to the other. The actual metals and electrolytes used control the voltage of the battery -- each different reaction has a characteristic voltage. For example, here's what happens in one cell of a car's lead-acid battery:

The cell has one plate made of lead and another plate made of lead dioxide, with a strong sulfuric acid electrolyte in which the plates are immersed.
Lead combines with SO4 (sulfate) to create PbSO4 (lead sulfate), plus one electron.
Lead dioxide, hydrogen ions and SO4 ions, plus electrons from the lead plate, create PbSO4 and water on the lead dioxide plate.
As the battery discharges, both plates build up PbSO4 and water builds up in the acid. The characteristic voltage is about 2 volts per cell, so by combining six cells you get a 12-volt battery.

A lead-acid battery has a nice feature -- the reaction is completely reversible. If you apply current to the battery at the right voltage, lead and lead dioxide form again on the plates so you can reuse the battery over and over. In a zinc-carbon battery, there is no easy way to reverse the reaction because there is no easy way to get hydrogen gas back into the electrolyte.

Modern Battery Chemistry

Modern batteries use a variety of chemicals to power their reactions. Typical battery chemistries include:

Zinc-carbon battery - Also known as a standard carbon battery, zinc-carbon chemistry is used in all inexpensive AA, C and D dry-cell batteries. The electrodes are zinc and carbon, with an acidic paste between them that serves as the electrolyte.

Alkaline battery - Alkaline chemistry is used in common Duracell and Energizer batteries, the electrodes are zinc and manganese-oxide, with an alkaline electrolyte.

Lithium-iodide battery - Lithium-iodide chemistry is used in pacemakers and hearing aides because of their long life.

Lead-acid battery - Lead-acid chemistry is used in automobiles, the electrodes are made of lead and lead-oxide with a strong acidic electrolyte (rechargeable).

Nickel-cadmium battery - The electrodes are nickel-hydroxide and cadmium, with potassium-hydroxide as the electrolyte (rechargeable).

Nickel-metal hydride battery - This battery is rapidly replacing nickel-cadmium because it does not suffer from the memory effect that nickel-cadmiums do (rechargeable).

Lithium-ion battery - With a very good power-to-weight ratio, this is often found in high-end laptop computers and cell phones (rechargeable).

Zinc-air battery - This battery is lightweight and rechargeable.

Zinc-mercury oxide battery - This is often used in hearing-aids.

Silver-zinc battery - This is used in aeronautical applications because the power-to-weight ratio is good.

As you can see, several of these batteries are rechargeable. What makes a battery rechargeable? In the next section, we'll check out how rechargeable batteries work.

Rechargeable Batteries

With the rise in portable devices such as laptops, cell phones, MP3 players and cordless power tools, the need for rechargeable batteries has grown substantially in recent years. The concept of the rechargeable battery has been around since 1859, when French physicist Gaston Plante invented the lead acid cell, which would later become the world's first rechargeable battery. That same chemistry is still used in today's car battery.

The basic idea behind the rechargeable battery is simple: when electrical energy is applied to the battery, the electron flow from negative to positive that occurs during discharge is reversed and power is restored. This requires an adapter in the case of devices with built-in batteries or for standard nickel-cadmium or nickel-metal hydride batteries, the most common multi-use rechargeable batteries used today in your remote control, flashlight or digital camera.

A Nickel-Metal Hydride AA batter charger

Car batteries are one of the oldest kinds of rechargeable batteries and in fact, the electric car predates its gas-powered cousin. In a standard car, there is a single lead-acid SLI battery that supplies power to the starter, lights and ignition system. The battery charger in this case is the alternator, a clever device that converts gasoline power to electrical energy and distributes it where needed. In electric and hybrid cars, traction batteries are used to power the vehicle down the road. Traction batteries come in many varieties, from lead acid, to nickel-cadmium, nickel metal hydride and lithium ion.

The recharging rate has improved substantially over the years and is broken down into three categories:

Slow: 14-16 hours
Quick: 3-6 hours
Fast: Less than one hour

The rate of charge is determined by how much electrical current is allowed into the battery by the charger. Some batteries can handle higher voltage in a shorter amount of time without overheating, while others need a lesser voltage applied over a longer period of time. The quicker the rate of charge, the more chance there is of over charging, which can ruin a battery's chance of holding its charge. The key in avoiding an over charge is the ability to dissipate the charging current once maximum power has been reached. Most chargers have built-in voltage regulators do this, allowing you to safely leave your cell phone or computer plugged in overnight.

The speed and effectiveness of the charge depends largely on the quality of the charger itself. Chargers vary in performance based on the price tag and like most products you get what you pay for. Chargers are generally designed for specific cell chemistries, although newer universal chargers have sensors built in that identify the cell type and react appropriately. There are also smart chargers that use a microprocessor to monitor temperature, voltage and state of charge, which is the percentage of power available compared to its full capacity.

One common problem in nickel-cadmium rechargeable batteries is something known as the memory effect. This is when the battery is continually recharged before it has discharged more than 50 percent of its power, causing it to essentially forget that it could fully discharge to begin with. Memory effect is caused by the formation of hard-to-dissolve cadmium crystals deep within the battery. Cadmium crystals are an unavoidable by-product of discharge; the trick is to keep them small enough to be reformed as cadmium during the charging process. When a battery is not fully discharged, the crystals deep within the battery are not affected by the influx of electrical current, so they are not reformed as cadmium and can grow into the troublesome larger cadmium crystals. The battery will still function normally, but is maxed out at 50 percent. The memory effect can be avoided by fully cycling the battery once every two to three weeks by allowing it to discharge completely, and then fully recharge.

It's important to remember that no battery, rechargeable or otherwise, will last forever. All batteries suffer from aging cells and the longer they are used, the less capacity they ultimately will have. Rechargeable batteries are still a great way to save money and reduce waste.

Now, let's take a look at battery arrangement.

Battery Arrangement and Power

In many devices that use batteries - such as portable radios and flashlights, you do not use just one cell at a time. You normally group them together serially to form higher voltages, or in parallel to form higher currents. In a serial arrangement, the voltages add up. In a parallel arrangement, the currents add up. The following diagram shows these two arrangements:

arrangement

The upper arrangement is called a parallel arrangement. If you assume that each cell produces 1.5 volts, then four batteries in parallel will also produce 1.5 volts, but the current supplied will be four times that of a single cell. The lower arrangement is called a serial arrangement. The four voltages add together to produce 6 volts.

Normally, when you buy a pack of batteries, the package will tell you the voltage and current rating. For example, a digital camera might use four nickel-cadmium batteries that are rated at 1.25 volts and 500 milliamp-hours for each cell. The milliamp-hour rating means, theoretically, that the cell can produce 500 milliamps for one hour. You can slice and dice the milliamp-hour rating in lots of different ways. A 500 milliamp-hour battery could produce 5 milliamps for 100 hours, or 10 milliamps for 50 hours, or 25 milliamps for 20 hours, or (theoretically) 500 milliamps for 1 hour, or even 1,000 milliamps for 30 minutes.

However, batteries are not quite that linear. For one thing, all batteries have a maximum current they can produce -- a 500 milliamp-hour battery cannot produce 30,000 milliamps for 1 second, because there is no way for the battery's chemical reactions to happen that quickly. And at higher current levels, batteries can produce a lot of heat, which wastes some of their power. Also, many battery chemistries have longer- or shorter-than-expected lives at very low current levels. But milliamp-hour ratings are somewhat linear over a normal range of use. Using the amp-hour rating, you can roughly estimate how long the battery will last under a given load.

If you arrange four of these 1.25-volt, 500 milliamp-hour batteries in a serial arrangement, you get 5 volts (1.25 x 4) at 500 milliamp-hours. If you arrange them in parallel, you get 1.25 volts at 2,000 (500 x 4) milliamp-hours.

Have you ever looked inside a normal 9-volt battery?

It contains six, very small batteries producing 1.5 volts each in a serial arrangement!

Batteries have proven to be one of the most important inventions of the 20th century and are becoming more so as we continue the shift toward a more mobile lifestyle. In the future, batteries will grow smaller, more powerful and longer lasting in order to keep up with our fast paced, portable world.

Electric Car

In an electric car, the accelerator pedal hooks to a pair of these to relay the information to the controller about how much power it should deliver.
batteries
power inverters
potentiometers

The accelerator pedal hooks to a pair of potentiometers (variable resistors), and these potentiometers provide the signal that tells the controller how much power it is supposed to deliver. The controller can deliver zero power (when the car is stopped), full power (when the driver floors the accelerator pedal), or any power level in between.

What is the purpose of two potentiometers?
to increase the cost
for durability
for safety

There are two potentiometers for safety's sake. The controller reads both potentiometers and makes sure that their signals are equal. If they're not, then the controller doesn't operate. This arrangement guards against a situation where a potentiometer fails in the full-on position.

The controller reads the setting from the potentiometer and rapidly switches the power to the motor on and off at a rate of how many times per second?
more than 15,000 times per second
more than 25,000 times per second
more than 50,000 times per second

The controller reads that setting from the potentiometer and rapidly switches the power to the motor on and off so that it is on half the time and off half the time. Most controllers pulse the power more than 15,000 times per second, in order to keep the pulsation outside the range of human hearing. The pulsed current causes the motor housing to vibrate at that frequency, so by pulsing at more than 15,000 cycles per second, the controller and motor are silent to human ears.

How many sets of transistors do you need in an AC controller?
six
three
one

The controller creates three pseudo-sine waves. It does this by taking the DC voltage from the batteries and pulsing it on and off. In an AC controller, there is the additional need to reverse the polarity of the voltage 60 times a second. Therefore, you actually need six sets of transistors in an AC controller, while you need only one set in a DC controller. In the AC controller, for each phase you need one set of transistors to pulse the voltage and another set to reverse the polarity. You replicate that three times for the three phases -- six total sets of transistors.

Electric cars can use AC or DC motors. According to the article, many of the DC motors used in electric cars come from where?
the electric garage door industry
the electric forklift industry
the electric vacuum cleaner industry

Electric cars can use AC or DC motors. If the motor is a DC motor, then it may run on anything from 96 to 192 volts. Many of the DC motors used in electric cars come from the electric forklift industry. If it is an AC motor, then it probably is a three-phase AC motor running at 240 volts AC with a 300 volt battery pack.
What is the weakest link in any electric car?

the potentiometers
the batteries
the driver

Right now, the weak link in any electric car is the batteries. There are at least six significant problems with current lead-acid battery technology: They are heavy, they are bulky, they have a limited capacity, they are slow to charge, they have a short life and they are expensive.

To keep the battery in an electric car charged, the car must have what?

an AC-to-DC converter
a DC-to-DC converter
a DC-to-AC converter

To keep the battery charged, an electric car needs a DC-to-DC converter. This converter takes in the DC power from the main battery array (at, for example, 300 volts DC) and converts it down to 12 volts to recharge the accessory battery. When the car is on, the accessories get their power from the DC-to-DC converter. When the car is off, they get their power from the 12-volt battery as in any gasoline-powered vehicle. The DC-to-DC converter is normally a separate box under the hood, but sometimes this box is built into the controller.

Any electric car needs this to recharge the batteries.
a potentiometer
a transistor
a charging system

Any electric car that uses batteries needs a charging system to recharge the batteries. The charging system has two goals: To pump electricity into the batteries as quickly as the batteries will allow, and to monitor the batteries and avoid damaging them during the charging process.

What is the term used when someone gently overcharges the batteries to make sure that the weakest cells are brought up to full charge?
equilibrium charge
equalization charge
equidistant charge

Because the batteries are in series, they get exactly the same amount of recharge, leaving the weak battery even weaker (relatively) than it was before. Over time, this results in one battery going bad long before the rest of the pack. The weakest-link effect means that this battery determines the range of the vehicle, and the usability of the car drops off. The common solution to the problem is "equalization charge." You gently overcharge the batteries to make sure that the weakest cells are brought up to full charge. The trick is to keep the batteries equalized without damaging the strongest batteries with overcharging.

If you've decided to build your own electric vehicle, you should know that an electric motor usually needs which one of the following for maximum efficiency?

a potentiometer
a catalytic converter
a reduction gear

Usually, the electric motor needs a reduction gear for maximum efficiency. The easiest way to create the gear reduction is to pin the existing manual transmission in first or second gear. It would save weight to create a custom reduction gear, but normally it is too expensive.

PICTORIAL DIAGRAM The simplest of all diagrams is the pictorial diagram. It shows a picture or sketch of the various components of a specific system and the wiring between these components. This simplified diagram provides the means to readily identify the components of a system, even if you are not familiar with their physical appearance. This type of diagram shows the various components without regard to their physical location, how the wiring is marked, or how the wiring is routed. It does, however, show you the sequence in which the components are connected. Figure 3-6 is a pictorial diagram of an automobile starting and ignition system. If you are not already familiar with the components of this system, study the diagram. You should then be able to recognize the physical appearance of each component and its interconnections with the other components of the system. Figure 3-6.—Pictorial diagram of automotive starter and ignition systems.




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