For the selection of super capacitors, power requirements, discharge time and system voltage changes play a decisive role. The output voltage drop of the supercapacitor consists of two parts, one is the energy release of the supercapacitor; The other part is caused by the internal resistance of supercapacitor. Who takes the lead depends on the time. In a very fast pulse, the internal resistance takes the lead. On the contrary, in a long time discharge, the capacitive part takes the lead.

Parameter selection

following Farad capacitor The basic parameters determine the size of the selected capacitor:

Super capacitor module. Operation voltage; Operation cut-off voltage; Average discharge current; How long is the discharge time.

Compared with batteries, supercapacitors have the following characteristics:

Super long life, charging and discharging more than 500000 times, 500 times of Li Ion battery, 1000 times of Ni MH and Ni Cd battery. If the super capacitor is charged and discharged 20 times a day, it can be used for 68 years in succession.

Capable of charging with large current, short charging and discharging time, simple requirements for charging circuit, no recall effect.

Ultra low series equivalent resistance (LOW ESR), power density is dozens of times more than lithium ion battery, suitable for high current discharge (a 4.7F capacitor can release an instantaneous current of more than 18A).

Maintenance free, sealable.

The temperature range is - 40 ℃~+70 ℃, and the general battery temperature is - 20 ℃~60 ℃.

Super capacitors can be formed in series and parallel Super capacitor module It can withstand pressure and store higher capacity.

Farad capacitor selection method:

Supercapacitors are different from batteries. In some applications, they may be better than batteries. Super capacitor manufacturer Sometimes it is a better way to combine the power characteristics of capacitors and the high energy storage of batteries.

The supercapacitor can be charged to any potential within its rated voltage scale and can be fully discharged. The super capacitor module battery is restricted by its own chemical reaction and operates at a narrow voltage scale. If it is over discharged, it may be damaged.

Supercapacitors can repeatedly transmit energy pulses without any ill effects. On the contrary, if the battery repeatedly transmits high-power pulses, its life will be greatly reduced.

Supercapacitors can be charged quickly while batteries can be damaged by fast charging.

Supercapacitors can repeat hundreds of thousands of cycles, while battery life is only a few hundred cycles.

The state of charge (SOC) of supercapacitors and the voltage constitute a simple function, while the state of charge of batteries contains a variety of miscellaneous conversions.

Supercapacitors can store more energy than conventional capacitors with appropriate volumes, and batteries can store more energy than supercapacitors with appropriate volumes. In some applications where power determines the size of energy memory devices, supercapacitors are a better approach.