Battery Terminology
Battery Terminology
● Ah (Ampere-hour) - A unit of current intensity, where 1 Ah indicates the maximum discharge current of 1 ampere for 1 hour.
● Ah Capacity - The ampere count during a single discharge of a rechargeable battery. The Ah capacity during discharge is determined by many factors, including the limiting voltage, the quantity and density of the electrolyte, the discharge rate, the design of the separator; the battery's lifespan, operating temperature, and usage conditions; the number of electrodes, electrode design, and electrode size.
● Anode - In primary or secondary batteries, the metal electrode that releases electrons to the load circuit and dissolves into the electrolyte.
● Hydrogen Cell - A battery with water as the electrolyte.
● Available Capacity - The total capacity of a battery that is typically expressed in ampere-hours or milliampere-hours. Available capacity is determined by the end voltage, the quantity and density of the electrolyte, battery lifespan, operating temperature, discharge rate, and battery usage conditions.
● Battery - A device that converts stored chemical energy into electrical energy, usually composed of two or more cells connected electrically. The term "battery" is also commonly used for a single cell, such as household batteries.
● Battery Types - Generally, there are two types of batteries: primary batteries and secondary batteries or rechargeable batteries. Primary batteries sometimes use the same active materials as secondary batteries, which are designed for continuous or intermittent discharge in a single use. Secondary batteries use materials that allow them to be partially or fully discharged and then recharged, with the current direction being reversed during discharge and charging. During charging after discharge, the anode plate or anode is in a higher oxidation state, while the cathode plate is in a lower state, thus restoring to the original charged state.
● Battery Capacity - The amount of electrical energy released by a battery under certain conditions (discharge rate, temperature, cut-off voltage, etc.), usually expressed in ampere-hours or watt-hours. The capacity in watt-hours is equal to the capacity in ampere-hours multiplied by the battery's voltage.
● Battery Charger - An electronic device used to charge rechargeable batteries.
● Charging Rate - The numerical value of the current during charging of a rechargeable battery.
● Cut-off Voltage - The specified lower limit voltage at which a battery is fully discharged. The specification of cut-off voltage or final voltage is for the effective utilization of battery capacity. Cut-off voltage varies depending on the type of battery, discharge rate, temperature, and battery usage conditions. "Cut-off voltage" is more commonly used for primary batteries, while "final voltage" is used for rechargeable batteries.
● C - The rated capacity at constant current discharge, measured in ampere-hours. For example, a C5 capacity indicates the ampere count of the battery during 5 hours of constant current discharge. The capacity of the same model battery can vary, such as the capacity of C5 is usually less than that of C20.
● Cathode - In primary or secondary batteries, the electrode that causes the anode to undergo oxidation reactions or receives electrons.
● Cell - An electrochemical device composed of an anode plate, cathode plate, separator, and electrolyte, capable of storing electrical energy. When a cell is placed in a container and connected with terminals, it becomes a battery cell.
● Charging - For rechargeable batteries, it is the process of converting electrical energy input from an external circuit into chemical energy stored in the battery. The principle involves passing direct current in the opposite direction of discharge to restore the active materials in the battery. A cell or battery is generally considered fully charged when it has been charged.
● Charge Rate - For rechargeable batteries, it refers to the constant current value required to charge to the rated capacity within a specified time. For example, a 500Ah battery with a C/10 charge rate can be expressed as:
C/10 Charge Rate = 500Ah / 10h = 50A
● State of Charge - The remaining capacity state of a battery.
● Charging - The process of converting electrical energy into stored chemical energy.
● Constant Current Charging - A charging method where the charging current remains constant during charging. Some lead-acid batteries' constant current charging includes initial current and final current.
● Constant Voltage Charging - A charging method where the voltage across the charger remains constant during charging.
● Cycle - A sequence of charge and discharge. Deep cycling requires the battery or battery pack to discharge all its energy to the specified terminal voltage each time. Shallow cycling, on the other hand, involves only partial energy consumption during each discharge, meaning the energy could be as high as 50% of any value.
● Cycle Life - The number of charge-discharge cycles a rechargeable battery can achieve before failure. In practice, when a battery or battery pack has used 80% of its ampere-hour capacity, it is usually considered to have reached the end of its life.
● Depth of Discharge - The percentage of the battery's capacity that is discharged.
● Discharge - The process of converting the chemical energy in a battery into electrical energy.
● Deep Discharge - Consuming all the electrical energy in a battery or battery pack before recharging, down to the termination voltage.
● High Rate Discharge - A short-duration, high-current discharge, usually less than one hour.
● Low Rate Discharge - A long-duration, low-current discharge, usually more than one hour.
● Consumption - The current flowing out of the battery.
● Dry Cell - A chemical battery that produces direct current with a paste electrolyte or where the electrolyte cannot flow. Typically refers to zinc-manganese batteries, which are common commercial types of batteries.
● Electrochemical Cell - A system in which the active materials within a battery provide stored electrical energy through an electrochemical reaction.
● Electrode - A conductor through which current enters or leaves the conducting medium.
● Electrolyte - A compound that can conduct electricity when dissolved in a solution or in a molten state. All electrolytes produce free ions that conduct electricity in a molten state or solution.
● Electropositivity - The ease with which an element loses electrons to become a cation. Elements with high electropositivity oxidize faster than those with low electropositivity.
● Discharge Cut-off Voltage - The voltage at which the battery ceases discharging.
● Energy - The output capability, expressed as capacity multiplied by voltage or watt-hours.
● Energy Density - The amount of energy stored in a given volume or mass of material (watt-hours/pound, watt-hours/cubic inch).
● Float Charging - A method of maintaining a charged battery connected to a constant-voltage direct current power source to keep it fully charged.
● Primary Cell - A device composed of two electrodes separated by an electrolyte, capable of converting chemical energy into electrical energy.
● Gas Evolution - The release of gas from one or both electrodes within a battery. Gas evolution is usually caused by self-discharge or the electrolysis of water in the electrolyte during charging.
● Internal Resistance - The resistance encountered by current flowing through the interior of the battery.
● Memory Effect - The automatic retention of a specific electrical performance by a battery after long-term exposure to a particular work cycle, preventing it from fully discharging its rated capacity and only reaching the discharge depth commonly used (usually occurs in nickel-cadmium batteries).
● Negative Electrode - The electrode that delivers electrons to the external circuit during battery discharge.
● Non-aqueous Solvent Battery - A battery that does not contain molten salts or organic electrolytes as non-aqueous solvents.
● Ohm's Law - The formula that describes the amount of electric current flowing through a circuit. Voltage = Current × Resistance
● Open Circuit - The state of a battery that is neither charging nor discharging (i.e., the circuit is open).
● Open Circuit Voltage - The potential difference between the positive and negative terminals of a battery when the external circuit is disconnected (i.e., under no-load conditions).
● Oxidation Reaction - A chemical reaction that releases electrons from the active material of an electrode.
● Parallel - Connecting several batteries' positive and negative terminals side by side, resulting in a battery pack with a voltage equal to that of a single battery and a current that is the sum of the currents of each battery.
● Polarity - The specific positive or negative state of two poles or the electrical state.
● Positive Electrode - The electrode that receives electrons from the external circuit during battery discharge.
● Primary Battery - A battery composed of primary cells.
● Primary Cell - A device that converts chemical energy into electrical energy through an electrochemical reaction, which is irreversible. Therefore, once a primary cell discharges, it cannot be effectively recharged. Note: When the usable energy of a battery decreases to zero, the battery is usually discarded. Primary cells can be further classified based on their electrolyte.
● Rated Capacity - The minimum amount of electrical energy that a battery should deliver under certain conditions.
● Rechargeable - Capable of being recharged, generally referring to secondary batteries or battery packs.
● Reduction - The chemical process of obtaining electrons from the active material of an electrode.
● Sealed - A structure that prevents the solvent or electrolyte of the primary cell from leaking out and blocks air from entering the battery (air can dry out the electrolyte or affect the chemical reaction).
● Self-discharge - The discharge that occurs in a battery when it is in an open-circuit state.
● Separator - An electrically insulating material construction that allows electrons to pass through but prevents electrical contact between the positive and negative electrodes.
● Storage Life - For dry cells, the period during which the battery maintains a specified percentage of its original energy (usually 90%) at a storage temperature of 21°C (69°F) (calculated from the date of manufacture).
● Short Circuit Current - The current generated in a circuit due to a short circuit (i.e., a low-resistance short connection between the positive and negative terminals).
● Starting Battery - A battery designed to start an internal combustion engine and power the vehicle's electrical system when the engine is not running. Such batteries can also be used for emergency lighting.
● Stationary Battery - A type of battery designed specifically for stationary locations.
● Secondary Battery - A battery that can be restored and reused after being discharged by charging.
● Storage Battery - An electrolytic cell that forms electrical energy, capable of storing electrical energy as chemical energy after the battery is discharged; when discharging is required, the chemical energy is converted back into electrical energy.
● Trickle Charging - A charging mode that provides a moderately high current rate. As the battery reaches a low charge state, the current is gradually reduced to a lower rate until the battery is fully charged.
● Terminals - The part of the battery that connects to the external circuit.
● Thermal Runaway - A phenomenon where an increase in temperature leads to abnormal heat generation in the charging battery, resulting in increased charging current, which can ultimately cause the battery to become damaged and dry out.
● Microcurrent Charging - A method of charging the battery at a low rate to maintain a full charge state.
● Ventilation Holes - A sealed mechanism that allows for the release of appropriate gases.
● Cut-off Voltage - The minimum operating voltage at which the battery should no longer be discharged during discharge.
● Terminal Voltage - The battery voltage that is lower than the voltage at which the connected device does not operate or lower than the specified voltage for device operation.
● Nominal Voltage - The voltage when the battery is fully charged at the rated current.
● Wet Battery - A type of battery where the electrolyte is liquid and can flow freely.
Editd by Richard
