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This calculator estimates the theoretical runtime of a battery under a given load. By entering battery configuration and load parameters, you can determine the expected duration of power supply. Parameter Description Connection -Select the battery connection type: --Series: Voltages add up, capacity remains unchanged --Parallel: Voltage remains constant, capacities add up Number of Batteries -Total number of batteries in the system. The total voltage and capacity are calculated based on the connection type. Voltage (V) -Nominal voltage of a single battery, in volts (V). Capacity (Ah) -Rated capacity of a single battery, in ampere-hours (Ah). Load (W or A) -Power consumption of the connected device. Two input options: --Power (W): In watts, suitable for most appliances --Current (A): In amperes, when operating current is known Peukert Constant (k) -A coefficient used to correct for capacity loss at higher discharge rates. Typical values by battery type: --Lead-Acid: 1.1 – 1.3 --Gel: 1.1 – 1.25 --Flooded: 1.2 – 1.5 --Lithium-Ion: 1.0 – 1.28 -An ideal battery has a Peukert constant of 1.0. Real batteries have values greater than 1.0, which typically increase with age. Depth of Discharge (DoD) -The percentage of battery capacity that has been discharged relative to full capacity.DoD = 100% - SoC (State of Charge). -Can be expressed in percent (%) or ampere-hours (Ah). In some cases, actual capacity exceeds rated capacity, so DoD may exceed 100%.

This tool calculates key parameters of transformer primary and secondary windings, such as voltage, number of turns, wire size, and resistance. Enter known values, select the parameter to calculate, and get instant results. Ideal for power supply design, repair, and learning.

Calculate the heat energy dissipated in resistive elements of a circuit. "Power dissipated in the form of heat in the resistive elements of the circuit." Key Formula: Joule's Law Q = I² × R × t or Q = P × t Where: Q : Heat energy (joules, J) I : Current (amperes, A) R : Resistance (ohms, Ω) t : Time (seconds, s) P : Power (watts, W) Note : Both formulas are equivalent. Use $ Q = I^2 R t $ when you know current and resistance. Parameter Definitions 1. Resistance (R) The tendency of a material to oppose the flow of electric current, measured in ohms (Ω). Higher resistance leads to more heat generation for the same current. Example : A 100 Ω resistor limits current and produces heat. 2. Power (P) Electrical power supplied or absorbed by a component, measured in watts (W). 1 watt = 1 joule per second. You can calculate it as: P = I² × R or P = V × I Example : A 5W LED uses 5 joules every second. 3. Current (I) The flow of electric charge through a material, measured in amperes (A). Heat is proportional to the square of the current — doubling current quadruples heat! Example : 1 A, 2 A, 10 A — each produces vastly different heat levels. 4. Time (t) Duration for which current flows, measured in seconds (s). Longer time → more total heat generated. Example : 1 second vs. 60 seconds → 60x more heat. How It Works When current flows through a resistor: Electrons move through the material They collide with atoms, losing kinetic energy This energy is transferred as vibrational energy → heat Total heat depends on: current, resistance, and duration The process is irreversible — electrical energy is lost as heat. Application Scenarios Designing heating elements (e.g., electric stoves, hair dryers) Calculating power loss in transmission lines Estimating temperature rise in PCB traces and components Selecting appropriate resistors based on power rating Understanding why devices get hot during operation Safety analysis in circuits (preventing overheating and fire risk)