I. Basic Terms

1. Battery

A device composed of two or more cells connected in series or parallel to store and release electrical energy.

2. Cell

The basic unit of a battery that generates electrical energy through chemical reactions.

3. Electrolyte

The medium used in batteries to conduct ions, which can be liquid, gel, or solid.

4. Cathode

The electrode from which electrons flow out of the battery, typically the positive electrode during discharge.

5. Anode

The electrode into which electrons flow during discharge, typically the negative electrode.

6. Capacity

The total amount of electrical energy a battery can provide under specific conditions, usually expressed in ampere-hours (Ah) or milliampere-hours (mAh).

7. Volt: 

The unit of measure for electrical potential or voltage.

8. Watt: 

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.

9. Watt-Hour (Watt-Hrs, WH)

The unit of measure for electrical energy expressed as watts x hours.

10. Open-Circuit Voltage (OCV)

The voltage of a battery when it is not connected to a load.

11. Working Voltage

The voltage of a battery when it is operating under load.

12. Cut-off Discharge Voltage

The minimum voltage at which a battery is considered to be fully discharged.

13. Charge Limit Voltage

The voltage at which a battery transitions from constant current charging to constant voltage charging during the charging process.

II. Maintenance and Fault Terms

1. Self-Discharge

The natural loss of electrical charge in a battery when it is idle.

2. Sulfation

The growth of lead sulfate crystals in lead-acid batteries, which can degrade battery performance.

3. Memory Effect

A phenomenon in nickel-cadmium batteries where repeated partial discharges lead to a decrease in capacity.

4. Overdischarge

Continuing to discharge a battery below its cut-off voltage, which can damage the battery.

5. Overcharge

Continuing to charge a battery after it has reached full charge, which can lead to damage.

6. Thermal Runaway

A condition during charging where the temperature and current in a battery increase mutually, potentially leading to damage or fire.

7. Leakage

The escape of electrolyte from the battery to the external environment. Leakage can be caused by manufacturing defects, external impacts, prolonged use, overcharging, or packaging issues.

8. Electrolyte Decomposition

The breakdown of electrolyte within the battery due to excess water or an insufficient electrochemical window, leading to gas generation, swelling, and leakage.

9. Packaging Issues

Corrosion of the aluminum-plastic film or packaging damage in soft-pack batteries can lead to leakage.

10. Leak Detection

Methods such as airtightness testing, red dye testing, and high-temperature/high-humidity testing are used to detect leakage in batteries.

11. Safety Vent

A device that allows gas to escape when the internal pressure of a battery becomes too high, preventing explosion.

12. Sealing Compound

A material used to seal the battery cover, casing, or terminals.

13. Vent Plug

A component used to seal the filling port while allowing gas to escape.

14. Exhaust Valve

A component that allows gas to escape when the internal pressure of the battery exceeds a set value.

III. Performance Indicator Terms

1. Energy Density

The amount of energy a battery can store per unit volume or weight, typically expressed in watt-hours per kilogram (Wh/kg) or watt-hours per liter (Wh/L).

2. Power Density

The amount of power a battery can output per unit weight or volume, typically expressed in watts per kilogram (W/kg) or watts per liter (W/L).

3. Cycle Life

The number of charge-discharge cycles a battery can complete under specific conditions.

4. Depth of Discharge (DoD)

The percentage of the battery's rated capacity that has been discharged.

5. State of Health (SoH)

The percentage of the battery's rated capacity that can still be achieved after a period of use or storage.

6. State of Charge (SoC)

The percentage of the battery's current charge relative to its rated capacity.

IV. Structural and Material Terms

1. Separator

An insulating material used to isolate the positive and negative electrodes to prevent short circuits.

2. Electrode Plate

The electrode in a battery used to store and release electrical energy.

3. Case

The outer shell used to encase the battery, typically made of plastic or metal.

4. Alloy

A mixture of metals used in electrodes, such as the cadmium alloy in nickel-cadmium batteries.

5. Jelly Roll

The structure formed by winding the positive and negative electrodes in cylindrical batteries.

6. Laminated Aluminum Plastic Film

The material used for the outer casing of soft-pack batteries.

V. Charging Terms

1. Constant Current Charging

Charging a battery with a constant current.

2. Constant Voltage Charging

Charging a battery with a constant voltage, where the current decreases as the battery voltage increases.

3. Float Charging

Maintaining a battery's charge with a low current.

4. Trickle Charging

Supplemental charging of a battery with a very low current to prevent self-discharge.

5. Fast Charging

Charging a battery to full capacity in a short time (e.g., within 2.5 hours).

6. Cut-off Voltage

The voltage at which charging or discharging is terminated.

7. Charge Efficiency

The ratio of the actual energy stored in the battery to the input energy during charging.