https://en.wikipedia.org/wiki/Thermoelectric_effect
Specifications:Material: Ceramic / Bismuth TellurideColor: WhiteParametric model: SP1848-27145Temperature(C): 150 degreeOpen-circuit voltage(V): 4.8V Current(MA):
20C/ 0.97V/ 225mA;
40C/ 1.8V / 368mA ;
60C/ 2.4V / 469mA ;
80C/ 3.6V/ 559mA;
100C/ 4.8V/ 669mA
Module weight: 25g / 0.89ozModule size: 4 * 4 * 0.4cm / 1.6 * 1.6 * 0.2inch (L * W * H)Package weight: 26g / 0.92ozPackage size: 14.5 * 10 * 0.4cm / 5.7 * 4 * 0.2inch (L * W * H)
Power chip size: 40MM long * 40MM wide * 3.4MM thick
One side of the word is close to the heat sink (cold end)
No word on the side of the heat absorption surface (hot end)
The red wire is connected to the positive pole, the black wire is connected to the negative pole, and the temperature difference can be used to generate electricity.
The parameters of SP1848-27145 are as follows:
Temperature difference 20 degrees: open circuit voltage 0.97V, power generation current: 225MA
Temperature difference 40 degrees: open circuit voltage 1.8V, power generation current: 368MA
Temperature difference 60 degrees: open circuit voltage 2.4V, power generation current: 469MA
Temperature difference 80 degrees: open circuit voltage 3.6V, power generation current: 558MA
Temperature difference 100 degrees: open circuit voltage 4.8V, power generation current: 669MA
The above values are for reference only. In actual use, wiring, and booster board, current will be lost.
Export version: SP1848-27145 use temperature between -40 degrees and 150 degrees
Features:- Small and lightweight, convenient for use.- Designed specifically for power generation.- Sealed for moisture protection and contain thermal elements formulated for optimum Seebeck power generation.- High temperature 150C, with NM static protection.Package includes:1 x Thermoelectric Power Module

TEG / TGM - short for Thermo-Electric (Power) Generator Module - is a thermoelectric power plant that works based on the Seebeck effect , where the heat energy from the temperature difference between the two surfaces of electronic components is converted into electrical energy. The semiconductor component with model number SP1848-27145measuring 40 x 40 x 3.4 mm is capable of generating electricity up to 3.2 Watt (4.8 Volts, 669 mA) when the heat difference on both sides of the surface of this electronic component reaches 100 ° C . At a temperature difference of 20 ° C the resulting power is 210 mW (0.97V, 225 mA).The following is the conversion table of heat difference to power (Watt), potential difference (V), and current (mA) along with the graph curve, it appears that the energy transformation is close to linear.