Supercapacitor Selection Guide
Supercapacitors (EDLCs) provide high power density and virtually unlimited cycle life for backup power, energy harvesting, and pulse power applications.
Energy Storage
Energy stored in a supercapacitor: E = 0.5 × C × V²
Usable energy depends on minimum operating voltage. Typical usable energy is 50-75% of total stored energy.
Series Connection
For higher voltage, connect cells in series:
- Voltages add, capacitance divides (Ctotal = C/n)
- Voltage balancing is essential - never connect in series without balancing
- Use active balancing for best efficiency, passive balancing for simplicity
Charging
Supercapacitors can charge in seconds but require current limiting:
- Simple resistor: R = (Vsupply - Vcap) / Icharge
- Dedicated charger ICs provide optimal charging profile
- Always include overvoltage protection (max 2.7V per cell)
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Frequently Asked Questions
1. How do I calculate required capacitance?
Use the energy formula: C = 2E / (Vmax² - Vmin²). For constant power: C = P × t / (0.5 × (Vmax² - Vmin²)). Example: 10W for 60 seconds, 5V to 3V: C = 2 × 10 × 60 / (25 - 9) = 75F. Always add 30% margin for tolerance and aging.
2. How do I connect supercapacitors for higher voltage?
Connect in series: voltages add, capacitance divides. For 5 cells at 2.7V: Vtotal = 13.5V, Ctotal = C/5. Voltage balancing is mandatory - use balancing resistors (1kΩ-10kΩ) or active balancing IC. Never connect in series without balancing - cell voltage imbalance can cause overvoltage and damage.
3. What is the minimum order quantity for HJC capacitors?
Minimum order quantities (MOQ) vary by product type: MLCCs typically 10,000-100,000 pieces depending on case size, Aluminum electrolytics 1,000-10,000 pieces, Film capacitors 500-5,000 pieces, Supercapacitors 100-1,000 pieces. As an authorized distributor, we stock common parts for immediate delivery and can support smaller quantities. For high-volume production, contact our sales team for pricing and scheduling.
4. Where can I get samples of HJC capacitors?
Samples of HJC capacitors are available through our authorized distributor network. You can request samples by contacting our sales team or through our website. Sample kits are available for each product family including MLCCs, electrolytics, film capacitors, and supercapacitors. Typical sample delivery time is 1-2 weeks depending on location and part availability.
5. Does HJC provide Spice models for simulation?
Yes, HJC provides Spice models for many of our capacitor products. These models include equivalent series resistance (ESR), equivalent series inductance (ESL), and capacitance values across frequency and temperature. Models are available for MLCCs, aluminum electrolytics, and film capacitors. Contact hjc's technical support team for application-specific design guidance and recommendations.