Precautions for Using GTCAP Supercapacitors

I. The recommended welding conditions for the product are flow welding, as shown in the figure below:

Please note the following during welding:

1. Do not immerse the capacitor in solder.

2. Do not touch any parts other than the terminal with the soldering iron.

3. If the capacitor comes into direct contact with the printed circuit board or indirectly through a metallic conductor, it may lead to product rupture.

4. If you wish to expand the scope of application, first familiarize yourself with the characteristics of welding to prevent abnormal current flow caused by improper soldering between the capacitor and the printed circuit board.

5. When using supercapacitors on double-sided circuit boards, ensure that the connection points do not pass through areas directly accessible to the capacitors, as this could lead to short circuits, overvoltage conditions, and potential damage to the capacitors. During installation and after installation, avoid forcibly twisting or tilting the capacitors, and never pull hard on the leads. Instead, carefully remove the pins and bend them before proceeding with soldering. Additionally, during the soldering process, take care to prevent overheating of the capacitors—specifically, for 1.6 mm printed circuit boards, the soldering temperature should be maintained at 260°C for no longer than 5 seconds. After soldering, thoroughly clean both the circuit board and the capacitors to ensure proper removal of any residual flux or contaminants.

6. Please refer to other instructions in the product specification sheet for further details.

II. Polarity Issues of Supercapacitors

Unlike conventional electrolytic capacitors or batteries, supercapacitors theoretically have no polarity because their positive and negative electrodes are made of the same material. However, the polarity markings on supercapacitors are determined by manufacturers during the production process. If a supercapacitor is accidentally used in reverse for a short period during operation, it will not cause substantial damage to the device; simply reversing it back to the correct orientation will restore normal functionality. Nevertheless, prolonged reverse usage can lead to rapid degradation of the capacitor's performance and significantly shorten its lifespan.

III. Regarding the Charging Issue of Supercapacitors

Supercapacitors require charging with a DC voltage not exceeding the rated voltage, and various charging methods can be employed, including current-limiting, constant-current, constant-power, and constant-voltage approaches. During the charging process, supercapacitors may cause a temporary drop in the voltage of the charging power supply until the capacitor is fully charged, at which point the system restores voltage equilibrium.

IV. Issues Related to the Internal Resistance and Capacitance of Supercapacitors

During the charge and discharge process, the IR drop caused by the internal resistance of supercapacitors reduces the charging and discharging efficiency of the capacitor. Therefore, the magnitude of the capacitor's internal resistance largely determines its overall quality. However, since supercapacitors inherently have higher internal resistance compared to conventional capacitors, they tend to generate heat when used in AC circuits or during high-frequency charge-discharge operations, leading to rapid degradation of their lifespan. This is precisely why supercapacitors are typically employed only in DC circuits.

Compared to conventional capacitors, supercapacitors exhibit a significantly larger time constant τ, resulting in longer charge and discharge times. Consequently, they are not suitable for continuous operation under high-current conditions, as this can lead to rapid degradation of their thermal performance. In terms of frequency characteristics, supercapacitors demonstrate limited capacitance at high frequencies due to the extended response times of positive and negative ions within the micropores of the carbon electrodes. Therefore, standard AC measurement equipment designed for conventional capacitors cannot be used to assess their capacitance; instead, testing must be conducted using the mAh-based method commonly employed for battery measurements.

V. Transportation and Storage

The product transportation process should prevent the product from getting damp. Storage temperature should be maintained between -30°C and 50°C, with relative humidity below 60%. The maximum humidity level must not exceed 85%, as higher humidity could lead to deterioration of capacitor performance due to moisture or cause rusting.

VI. Supercapacitor Short-Circuit Detection

The short-circuited capacitor should not be able to charge or discharge. When a DC voltage is applied across the capacitor's positive and negative terminals, if the capacitor voltage fails to rise, it can be determined that the capacitor is short-circuited. When testing with a multimeter, a new capacitor will behave as expected in this scenario.

When charging, measuring with the ohmmeter set to the short-circuit range indicates a short-circuit condition, which is normal. However, this does not necessarily confirm that the capacitor itself is shorted. Instead, observe whether the resistance value increases; if it does, the capacitor is not shorted.

VII. Issues Related to Series and Parallel Connections

When identical supercapacitors are used in series: Total voltage = Number of cells × Single-cell voltage rating; Total capacitance = Single-cell capacitance ÷ Number of cells; Total energy = Number of cells × Single-cell capacitance; Total internal resistance = Number of cells × Single-cell internal resistance.

The voltage balancing issue among individual cells becomes particularly critical when three or more cells are connected in series. To address this, it is essential to incorporate a balancing circuit that ensures capacitors are not subjected to overvoltage conditions during prolonged operation. Overvoltage can lead to accelerated capacitor degradation and even damage. Additionally, supercapacitors of different specifications must not be used in series under any circumstances.

When supercapacitors are used in parallel, capacitors with different capacitance values can be connected in parallel and charged to the same voltage. However, it is important to address the issue of current balance among the individual capacitors and ensure proper isolation between them. This precaution helps prevent reverse charging caused by potential differences after discharge.

VIII. For other usage-related issues, please consult the manufacturer or refer to the relevant technical documentation provided in the GTCAP Supercapacitor User Manual.