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.

absorbent glass mat

AGM. A separator made of fiberglass material placed between the cathode and anode in a sealed lead-acid battery. Absorbent glass mat material holds the liquid electrolyte to prevent battery leakage.

acid

A corrosive chemical substance. Acid mixtures may be used as electrolytes in batteries.

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 may be used as electrolytes in batteries.

alkaline battery

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

alloys

A uniform mixture of two or more materials, one of which must be metal. An alloy of hydrogen-absorbing metals is used as the anode in nickel-metal hydride batteries.

amperage

A measurement of the amount of current flowing in a circuit. Amperage is measured in amperes (A).

ampere-hours

Ah. A unit used to express current output over time. Ampere-hours, or amp-hours, can be calculated by multiplying amperes by hours.

amperes

A. A unit of electrical measurement that describes both an amount of electricity and the time it takes for electricity to travel a certain distance. One ampere, or amp, equals one coulomb per second.

amp-hour

Ah. A unit used to express current output over time. Amp-hours, or ampere-hours, can be calculated by multiplying amps by hours.

amps

A. A unit of electrical measurement that describes both an amount of electricity and the time it takes for electricity to travel a certain distance. One amp, or ampere, equals one coulomb per second.

anode

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

atmospheric pressure

The amount of force exerted by the air. Atmospheric pressure can affect a battery's service and shelf life.

battery

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

battery management system

BMS. A computer that monitors, regulates, and coordinates the operations of a battery pack. The battery management system helps to prevent overheating and thermal runaway.

battery pack

A group of battery cells connected together to produce large amounts of electrical energy. Battery packs may also include components such as sensors and battery management systems.

brass

A nonferrous metal alloy of copper and zinc. Brass offers a balance of electrical and thermal conductivity and strength.

button cell

A small, button-like primary cell battery. Button-cell batteries provide power for very small devices like watches.

C rating

A measurent indicating the amount of time a battery can safely charge or discharge at a certain amperage. C ratings for charging are typically different from discharge C ratings for most 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.

capacity testing

The process of checking the amount of time it takes for a fully charged battery to fully discharge. Capacity testing, or load testing, can help determine how different loads, operating conditions, and environmental conditions can affect battery capacity.

carbon

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

carbon nanotubes

A hollow cylindrical molecule made of graphene. Carbon nanotubes are lightweight and energy dense and can be used to print small, intricate batteries.

carbon-zinc battery

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

cathode

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

cells

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.

chemical energy

The energy created by a reaction between two or more substances. Chemical energy is stored in batteries.

circuit

A completely enclosed path of electrical current consisting of various devices. Electrical circuits usually include a source, path, load, and control.

cold cranking amperage

CCA. A rating that indicates a battery's ability to provide start-up current in cold temperatures. Cold cranking amperage is measured at 0⁰F (-18⁰C).

compound

A substance consisting of two or more different elements in fixed proportions. Compound materials may be used to achieve certain properties in battery electrodes.

cranking amperage

CA. A rating that indicates how much start-up current a battery can produce before voltage drops below usable levels. Cranking amperage is measured for 30 seconds at 32⁰F (0⁰C).

current

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

cutoff voltage

The level of charge, in volts, at which a battery is considered fully discharged. Cutoff voltage determines when a battery should be charged and can help measure battery capacity.

cycle

The process of a battery completely discharging and then fully recharging. Cycle life indicates how many times a rechargeable battery can cycle before failing.

cycle life

The total number of times a secondary cell battery can be discharged and recharged before it must be replaced. Cycle life can be affected by how the battery is used and maintained over time.

cylindrical cell

A type of rechargeable battery cell enclosed in a rigid, tube-shaped can. Cylindrical cells provide more power than prismatic cells and are common in high-performance applications.

DC

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

digital multimeter

DMM. A device that can measure the voltage, current, and resistance of a circuit. Digital multimeters can be used to test a battery throughout its life.

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 decreases 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 performing work. Downtime occurs during maintenance activities such as battery charging or testing.

dry-cell batteries

A battery containing a paste electrolyte. Dry-cell batteries include many primary cell batteries.

electric vehicles

EVs. A vehicle that uses full or partial electric motor power to propel itself forward. Electric vehicles require high energy batteries.

electrical energy

A form of power created by the movement of electrons. Chemical energy is converted to electrical energy by batteries.

electrical load

A component on an electrical circuit that consumes electrical energy. Electrical loads in a battery circuit consume energy created by the battery's chemical reaction.

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 from most reactive, or most likely to give up electrons, to least reactive. The electromotive series is used to select metals used in batteries.

electrons

A negatively charged particle that orbits the center of an atom. Electrons play an integral role in conducting current.

energy density

The amount of energy that a battery can supply per unit of volume. Energy density is measured in watt-hours per liter (Wh/l).

EVs

Electric vehicles. A vehicle that uses full or partial electric motor power to propel itself forward. EVs require high energy batteries.

flat discharge curve

A graphical representation of a battery's voltage levels that indicates voltage remains relatively consistent until the battery is almost discharged. Flat discharge curves are desirable because they reflect how the battery's power output remains constant while discharging.

flooded lead-acid batteries

A type of lead-acid battery that is unsealed and uses a liquid electrolyte. Flooded lead-acid batteries must remain in an upright position to avoid leakage.

fossil fuels

Naturally occurring organic material 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 gas within a battery, usually due to overcharging. Gassing causes excess heat inside a battery cell that can damage the cell.

gel cells

A type of sealed lead-acid battery that uses a semi-solid electrolyte to eliminate some of the drawbacks of regular lead-acid batteries. Gel cells prevent leakage of the battery's sulfuric acid electrolyte.

generators

A device that converts mechanical energy into electrical energy. Generators may be powered by secondary cell batteries.

graphene

A carbon material formed from a single atomic layer of graphite, a crystalline form of carbon. Graphene is lightweight and energy dense.

graphite

A soft, black form of carbon that is semi-metallic. Graphite is highly conductive.

hot cranking amperage

HCA. A rating that indicates a battery's ability to provide start-up current in warm temperatures. Hot cranking amperage is measured at 80⁰F (27⁰C).

humidity

The presence of water vapor or moisture in the air. Excessive humidity affect the quality and performance of a battery.

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.

infrared thermometer

A device that measures the temperature of an object by sensing its thermal radiation. Infrared thermometers can be used to determine the temperature of battery cells.

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.

ions

A charged atom or molecule. An ion can be either positive or negative depending on whether it has a shortage or surplus of electrons.

kilowatt-hours

kWh. A unit used to measure large amounts of electrical power usage or delivery over time. One kilowatt-hour is equal to 1000 watt-hours.

lead

A gray metal that is soft and heavy. Lead is less conductive than other metals but can produce energy by reacting with surlphuric acid.

lead dioxide

A toxic compound of lead and oxygen that is brown in color. Lead dioxide is used as the cathode in lead-acid batteries.

lead-acid battery

A secondary cell battery that consists of a lead anode and a lead dioxide cathode in a sulfuric acid electrolyte. Lead-acid batteries typically produce about 2.2 volts per cell.

Li-ion battery

Lithium-ion battery. A secondary cell battery that uses a lithium compound as the cathode and, usually, a graphite anode and a lithium salt electrolyte. Li-ion batteries are common in a range of devices, from laptops to electric vehicles.

Li-ion battery

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

lithium

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

lithium iron phosphate batteries

LiFePO4 batteries. A type of rechargeable battery that contains lithium iron phosphate in the cathode and graphite, a form of carbon, in the anode. Lithium iron phosphate batteries are durable batteries that are resistant to thermal runaway.

lithium metal battery

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

lithium polymer battery

Li-poly battery. A type of lithium-ion battery that uses a polymer material to act as both the separator and the electrolyte. Lithium polymer batteries can be shaped to fit into small, thin, or irregularly shaped devices.

lithium-ion battery

Li-ion battery. A secondary cell battery that uses a lithium compound as the cathode and, usually, a graphite anode and a lithium salt electrolyte. Lithium-ion batteries are common in a range of devices, from laptops to electric vehicles.

lithium-sulfur batteries

Li-S batteries. A type of rechargeable battery that contains sulfur in the cathode and lithium in the anode. Lithium-sulfur batteries have higher energy density than lithium-ion batteries.

load testing

The process of checking the amount of time it takes for a fully charged battery to fully discharge. Load testing, or capacity testing, can help determine how different loads, operating conditions, and environmental conditions can affect battery capacity.

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. The memory effect occurs in batteries that are consistently recharged before they are fully discharged.

milliampere-hours

mAh. A unit used to express current output over time for smaller batteries. One milliampere-hour, or milliamp-hour, is equal to one thousandth of an ampere hour.

nanotechnology

A science and engineering field that involves working with atoms and molecules with dimensions less than 100 nanometers. Nanotechnology can be used to develop extremely small battery devices.

NiCad battery

Nickel-cadmium battery. A secondary cell battery that consists of a nickel cathode and a cadmium anode in an alkaline electrolyte. NiCad batteries 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 battery. A secondary cell battery 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 battery. A secondary cell battery that consists of a nickel cathode and an anode of hydrogen-absorbing alloys 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.

nominal capacity

The original capacity of a battery as specified by the manufacturer. The nominal capacity is used as a reference to determine a battery's condition throughout its life.

oxidize

To release or remove electrons from an atom, an ion, or a molecule. Metals that are more likely to oxidize are often used as the anode in batteries.

parallel

Connected across components. In parallel, the positive terminals of cells are connected to other positive terminals, then the negative terminals are connected to other negative terminals, to increase a battery capacity capacity.

personal protective equipment

PPE. Any article of clothing or device worn to minimize exposure to hazards and prevent injury. Common personal protective equipment for safe battery handling includes arc-rated clothing and insulated gloves.

power

The rate at which a device converts electrical energy into another form of energy, such as heat, movement, or light. Power is measured in watts (W).

power source

A device in a mechanical system that generates electricity. Power sources include batteries, electric motors, and generators.

pressure relief valve

A ventilation device on a battery that allows the release of accumulated gasses. Pressure relief valves help prevent the buildup of hydrogen gasses in SLA batteries.

primary cell batteries

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

prismatic cell

A type of rechargeable battery cell enclosed in a rigid, rectangular can. Prismatic cells are easy to stack and store more energy per cell than cylindrical cells.

rechargeable battery

A battery that can be recharged. Rechargeable batteries, or secondary cell batteries, are usually wet-cell batteries.

renewable energy

A type of 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 a more accurate indicator of battery life than ampere-hours or watt-hours.

salt

A chemical compound with a crystalline structure. Salt mixtures may be used as the electrolyte in batteries.

sealed lead-acid battery

SLA. A type of lead-acid battery that uses a semi-solid electrolyte to eliminate some of the drawbacks of regular lead-acid batteries. Sealed lead-acid batteries prevent leakage of the battery's electrolyte and can be used in any position.

secondary cell battery

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

self-discharge

The capacity loss that batteries experience during storage. Self-discharge occurs because of internal leakage between a battery's electrodes.

separator

A film in a battery cell that provides a barrier between the anode and cathode. Separators allow ions to pass through when the battery is charging or discharging but prevent the flow of ions when the battery is not in use.

series

Connected end-to-end along a single electrical path. In series, the negative terminal of one battery cell is connected to the positive terminal of the following cell to increase battery voltage.

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 levels that indicates voltage begins to decrease almost immediately and continues to decrease gradually as the battery is discharged. Sloping discharge curves are undesirable because they indicate how the battery's power output decreases while discharging.

sodium-ion batteries

NIB batteries. A type of rechargeable battery that contains sodium in the cathode. Sodium-ion batteries have lower energy density than lithium-ion batteries.

solid-state batteries

A type of rechargeable battery that contains a solid electrolyte and lithium in the cathode and anode. Solid-state batteries are more structurally stable than conventional Li-ion batteries because there is no risk of electrolyte leakage.

specific gravity

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

state of charge

SoC. The amount of energy, given as a percentage, that is currently contained in a battery. State of charge must be monitored in Li-ion batteries to prevent over and undercharging and to promote cell balancing.

state of health

SoH. A measurement of a battery's condition or performance compared to its original specifications that is based on voltage, internal resistance, and other conditions. State of health decreases over time due to several factors, including charge and discharge cycles, operating temperature, and damage to the battery.

sulfation

A phenomenon that occurs in lead-acid batteries when lead sulfate flakes off the electrodes 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 made of sulfur, oxygen, and hydrogen. Sulfuric acid is used as the electrolyte in lead-acid batteries.

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.

terminals

A conductive component on an electrical device to which other components can be attached. Terminals have a negative or a positive charge.

thermal runaway

The process of a defective or damaged battery cell overheating and damaging nearby cells, causing them to also overheat. Thermal runaway can cause fires or explosions if not detected and stopped.

thermal sensors

A sensing device used to measure the temperature of a system or environment. Thermal sensors work by detecting thermal energy and converting it into an electrical signal that can be processed and analyzed to determine temperature.

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.

volts

V. A unit used to measure electromotive force or pressure, which is called voltage. One volt of force is needed to cause one coulomb to do one unit of work.

volume

The amount of three-dimensional space that an object occupies in units of cubic inches, cubic meters, or liters. Volume is an important consideration for measuring a battery's energy density.

watt-hours

Wh. A unit used to measure electrical power usage or delivery over time. Watt-hours are equal to ampere-hours multiplied by volts.

watts

W. A unit used to measure the wattage or power used in or produced by a circuit. Watts are equal to amperes multiplied by volts.

wet-cell batteries

A battery containing a liquid electrolyte. 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.