Battery Selection 321

3-D printing

The process of joining or solidifying materials to make an object based on a three-dimensional computer model. 3-D printing, or additive manufacturing, methods typically build up layers of material to create an object.

acid

A corrosive chemical substance with a sour flavor. Acid mixtures are conductive electrolytes.

additive manufacturing

The process of joining or solidifying materials to make an object based on a three-dimensional computer model. Additive manufacturing, or 3-D printing, methods typically build up layers of material to create an object.

alkaline

A substance that is notable for its low number of hydrogen ions. Alkaline mixtures are conductive electrolytes.

alkaline battery

A primary cell that consists of a zinc anode and a manganese dioxide cathode in an alkaline electrolyte. Alkaline batteries are small, lightweight, and durable.

alloy

A uniform mixture of two or more materials. Alloys consist of at least one metal material.

alternator

A device that generates alternating current. An alternator converts mechanical energy into electrical energy through the use of a mechanical device like an engine.

amp hours

Ah. The units most commonly used to express battery capacity. Amp hours are a product of current and time.

anode

The negative electrode in a battery. The anode reacts with the cathode to release electrical energy.

atmospheric pressure

The weight of the atmosphere. Atmospheric pressure refers to the amount of pressure exerted by the air.

battery

A device that converts chemical energy into electrical energy. Batteries are a source of direct current.

button-cell battery

A small, button-like battery that provides power for watches and very small devices. Button-cell batteries are primary cell batteries.

CA

Cranking amperage. A rating used to measure how much start-up current a battery can produce before voltage drops below usable levels. CA is measured for 30 seconds at 32° F (0° C).

cadmium

A bluish-white metal that is soft and malleable. Cadmium is toxic to humans.

capacity

The amount of energy a battery can provide. Capacity depends on battery materials and volume.

carbon

A common nonmetallic element that exists in several forms, including graphite. Carbon can be conductive in some forms, such as graphite.

carbon nanotubes

Hollow cylindrical molecules made of graphene. Carbon nanotubes are lightweight and energy-dense.

carbon-zinc battery

A primary cell that consists of a zinc anode and a cathode made of manganese dioxide mixed with powdered carbon in an acidic electrolyte. The carbon-zinc battery was the first primary cell available for commercial use.

cathode

The positive electrode in a battery. The cathode reacts with the anode to release electrical energy.

cell

A single unit of a battery. A cell contains two different metals in an electrolyte solution.

charging cycle

The process of restoring the chemical reactivity of a secondary cell battery. The charging cycle involves forcing DC back through the system.

circuit

A controlled path for electricity. A circuit includes a source, path, load, and control.

cold cranking amperage

CCA. A rating of a battery's ability to provide start-up current in cold temperatures. Cold cranking amperage is measured at 0°F (-18°C).

compound

A substance consisting of the atoms of two or more different elements in fixed proportions. Compounds can only be broken down by chemical processes.

cranking amperage

CA. A rating used to measure how much start-up current a battery can produce before voltage drops below usable levels. Cranking amperage is measured for 30 seconds at 32°F (0°C).

current

The flow of electricity. Current strength is measured in amperes (A).

cycle

Completely discharge and fully recharge. Cycle life indicates how many times a rechargeable battery can cycle before failing.

cycle life

The total number of cycles a battery is capable of producing before it must be replaced. Cycle life applies to rechargeable batteries only.

direct current

DC. Electricity that travels in one direction. Direct current does not reverse the direction of flow.

discharge curve

A graph charting the voltage level of a battery as it drops off during use. The discharge curve depends on the rate of internal resistance.

discharging cycle

The chemical reaction process of a battery. The discharging cycle is complete when a battery can no longer react to produce voltage.

downtime

The period of time when a machine or device is not operating or producing. Downtime occurs during maintenance such as battery charging or testing.

dry-cell batteries

A device containing a paste electrolyte that converts chemical energy into electrical energy. Dry-cell batteries include many primary cell batteries.

electric motor

A machine that converts electricity into mechanical energy or motion. Electric motors operate on the principle of magnetic induction.

electrodes

A device within a circuit that conducts electricity. Electrodes have a positive or negative charge.

electrolyte

A conductive solution containing an acid, an alkaline, or a salt. The electrolyte in a cell or battery connects the two electrodes.

electromotive series

A list of metals in order of most reactive, or most likely to give up electrons, to least reactive. The electromotive series lists metals that are used in batteries.

energy density

The ratio of a battery's energy-delivery capability to its weight or volume. Energy density is measured in watt-hours per pound or watt-hours per cubic inch.

flat discharge curve

A graph of a battery's voltage levels that indicates that voltage remains relatively steady until the battery is nearly discharged. Flat discharge curves reflect favorable battery conditions.

fossil fuel

Naturally occurring organic fuel formed in the Earth's crust that can be burned to release stored energy. Fossil fuels include petroleum, coal, and natural gas.

gassing

A buildup of flammable hydrogen within a battery, usually due to overcharging. Gassing can be prevented with pressure release valves.

gel cells

A type of lead-acid battery that uses a semisolid electrolyte to eliminate some of the drawbacks of regular lead-acid batteries. Gel cells are also called sealed lead-acid batteries.

graphene

A crystalline carbon material that consists of a single layer of graphite atoms. Graphene is lightweight and energy-dense.

graphite

A soft, black form of carbon that is semimetallic. Graphite is highly conductive.

hot cranking amperage

HCA. A rating of a battery's ability to provide start-up current in warm temperatures. Hot cranking amperage is measured at 80°F (27°C).

hybrid electric vehicles

Vehicles powered by two different sources: an electrical system and a conventional internal combustion engine. Hybrid electric vehicles use much less gas than conventional gas-powered vehicles.

hydrogen

A colorless, odorless gas that is the most abundant element on the planet. Hydrogen can build up in batteries and lead to gassing.

hydrometer

A device used to measure the specific gravity of a fluid. A hydrometer consists of a sealed graduated tube with one weighted end.

internal resistance

The natural ohmic value of the electrodes in a battery. Internal resistance causes a battery's voltage to be lower with a load than without a load and to decrease over the course of discharge.

lead

A gray metal that is soft and heavy. Lead is a poor electrical conductor.

lead dioxide

A toxic compound of lead and oxygen that is brown in color. Lead dioxide is used as an oxidizing agent.

lead-acid battery

A secondary cell that consists of a lead anode and a lead dioxide cathode in a sulfuric acid electrolyte. Lead-acid batteries are rugged and inexpensive.

lithium

A lightweight, silver-white metal that is highly reactive. Lithium is often used in batteries because it is extremely energy-dense.

lithium battery

A primary cell that uses metallic lithium as the anode. Lithium batteries typically use manganese dioxide as the cathode and a lithium salt as the electrolyte.

lithium polymer battery

Li-poly. A type of lithium-ion battery that has an extremely flexible casing. Lithium polymer batteries can be shaped to fit into small, thin, or irregularly-shaped devices.

lithium-ion battery

Li-ion. A secondary cell that uses a lithium compound as the cathode. Lithium-ion batteries typically use graphite as the anode and a lithium salt as the electrolyte.

manganese dioxide

A naturally occurring compound of manganese and oxygen that is dark brown or black in color. Manganese dioxide is commonly used as the cathode in dry-cell batteries.

memory effect

A phenomenon occasionally seen in nickel-based batteries that lose the ability to produce voltage beyond a certain point. Memory effect occurs in batteries that are consistently recharged before they are fully discharged.

milliamp hours

mAh. Units used to express capacity for smaller batteries. Milliamp hours are a product of current and time, like amp hours, except a milliamp is one thousandth of an amp.

nanotechnology

The science of working with atoms and molecules to develop extremely small products and devices. Nanotechnology deals with dimensions less than 100 nanometers.

NiCad

Nickel-cadmium battery. A secondary cell that consists of nickel and cadmium electrodes in an alkaline base. NiCads have a flat discharge curve and can cycle thousands of times, but they may suffer from the memory effect.

nickel

A silver-white metal that is hard but malleable. Nickel forms the cathode for several rechargeable batteries.

nickel-cadmium battery

NiCad. A secondary cell that consists of a nickel cathode and a cadmium anode in an alkaline electrolyte. Nickel-cadmium batteries have a flat discharge curve and can cycle thousands of times, but they may suffer from the memory effect.

nickel-metal hydride battery

NiMH. A secondary cell that consists of a nickel cathode and an alloy anode in an alkaline electrolyte. Nickel-metal hydride batteries are popular alternatives to nickel-cadmium batteries because they are more environmentally friendly, have higher capacity, and show a reduced memory effect.

oxidize

To release or remove electrons from an atom, an ion, or a molecule. Oxidization is used to rank the metals on the electromotive series.

primary cell battery

A battery that cannot be recharged. Primary cell batteries are usually dry-cell.

renewable energy

Energy that is naturally and continually replenished without being depleted. Renewable energy sources include sunlight and wind.

reserve capacity

RC. The number of minutes a battery can maintain a useful voltage while continuously discharging 25 amps. Reserve capacity is often a truer test of battery life than amp hours.

salt

A chemical compound with a crystalline structure. Salt mixtures are conductive electrolytes.

sealed lead-acid battery

SLA. A type of lead-acid battery that uses a semisolid electrolyte to eliminate some of the drawbacks of regular lead-acid batteries. Sealed lead-acid batteries are also called gel cells.

secondary cell battery

A battery that can be recharged. Secondary cell batteries are usually wet-cell.

self-discharge

Capacity loss that batteries experience during storage. Self-discharge occurs because of internal leakage between a battery's metal plates.

service life

The length of time a battery is expected to operate before it must be replaced. The service life of a rechargeable battery is the same as its cycle life.

shelf life

The length of time a battery can remain in storage without losing capacity. Shelf life is determined by the battery's rate of self-discharge.

short circuit

An unwanted electrical condition in which current takes a shorter, unintended path between two conductors. A short circuit causes excess current flow.

sloping discharge curve

A graph of a battery's voltage level that indicates that voltage drops almost immediately and gradually decreases as the battery is discharged. Sloping discharge curves reflect unfavorable battery conditions.

specific gravity

The ratio of the volume and weight of a substance to an equal volume and weight of water. Specific gravity is generally a good judge of a substance's electrochemical usefulness.

sulfation

A phenomenon that occurs in lead-acid batteries when lead sulfate flakes off the plates and falls to the bottom of the cell, where it can no longer react and produce energy. Sulfation may be caused by overcharging or environmental conditions and leads to permanent capacity loss.

sulfuric acid

A highly corrosive, oily acid. Sulfuric acid is widely used in industry.

TCO

Total cost of ownership. An estimate of all the direct and indirect expenses associated with a purchase. The TCO of a battery takes into account several factors, such as rechargeability, reliability, and maintenance, as well as initial cost.

total cost of ownership

TCO. An estimate of all the direct and indirect expenses associated with a purchase. The total cost of ownership of a battery takes into account several factors, such as rechargeability, reliability, and maintenance, as well as initial cost.

voltage

The electrical pressure or potential that pushes electrons through a conductor. Voltage is measured in volts (V) and is also called electromotive force.

volume

The amount of three-dimensional space that an object occupies. Volume is measured in cubic inches or cubic meters.

wet-cell batteries

A device containing a liquid electrolyte that converts chemical energy into electrical energy. Wet-cell batteries include many secondary cell batteries.

zinc

A bluish-white metal that is malleable and corrosion-resistant. Zinc is often used as the anode in dry-cell batteries.