AW-PZ-2R7-505

The AW-PZ-2R7-505 is rated for maximum pulse current of 2A for durations up to 1 second. This rating is limited by the cell's 150mΩ ESR and thermal constraints of the thin packaging. At 2A, the voltage drop across ESR is approximately 0.3V (2A × 0.15Ω), which should be considered in system design. For longer pulses, the current should be derated to prevent excessive heating. Continuous current is limited to 0.3A to maintain safe operating temperatures. The pulse capability makes this cell ideal for wireless transmission bursts, LED flash, and haptic feedback applications typical in wearables. For higher current requirements, consider parallel connection of multiple cells or selecting a higher capacitance model with lower ESR.

For pulse currents above 2A, parallel multiple cells or select the 10F model with lower ESR.

The AW-PZ-2R7-505 should be charged using a current-limited power source or dedicated supercapacitor charger IC. Maximum recommended charge current is 0.5A (0.1C rate) for standard charging. Fast charging up to 2A is possible but will reduce cycle life slightly. The cell can be charged from any voltage source capable of providing 2.7V with current limiting. Simple charging can be implemented using a resistor in series with a voltage source, though this is inefficient. Better solutions use active current limiting circuits or dedicated charger ICs that provide constant current followed by constant voltage (CC-CV) charging profile. Charge time from 0V to 90% is approximately 5 × R × C when using resistor limiting, or about 120 seconds at 0.5A constant current. Always include overvoltage protection to prevent exceeding 2.7V.

Use a dedicated supercapacitor charger IC for optimal performance and safety. Contact our FAE team for recommended charger ICs and reference circuits.

The AW-PZ-2R7-505 exhibits typical EDLC self-discharge behavior with leakage current less than 0.02mA at 25°C after 72 hours. This corresponds to a voltage drop of approximately 15-20% in the first 24 hours after charging to 2.7V, followed by slower discharge. The self-discharge rate follows the logarithmic decay pattern common to all EDLC supercapacitors. At elevated temperatures, self-discharge increases significantly - approximately doubling for every 10°C rise. At 65°C, leakage current may reach 0.08mA. For applications requiring energy retention beyond 48 hours, periodic maintenance charging or alternative energy storage should be considered. The self-discharge characteristic is a fundamental property of the EDLC technology and must be accounted for in system power budgets.

If your application requires energy retention beyond 48 hours, consider implementing a maintenance charging circuit or contact us for alternative solutions.

Yes, the AW-PZ-2R7-505 can be connected in series for higher voltage applications, but active voltage balancing is essential for reliable operation. When series-connected, voltage imbalance occurs due to cell-to-cell variations in capacitance and leakage current. Without balancing, individual cells may exceed their 2.7V rating, causing accelerated degradation. For two cells in series (5.4V total), simple passive balancing using 1kΩ resistors may be sufficient for low-duty applications. For three or more cells, active balancing using dedicated ICs is strongly recommended. The balancing circuit should equalize both charge and discharge cycles. Cells should be from the same production batch to minimize parameter variation. The series configuration reduces total capacitance (C_total = C_cell / n) while multiplying voltage (V_total = V_cell × n).

For series applications of 3+ cells, use an active balancing IC. Contact our FAE team for balancing circuit recommendations.

The AW-PZ-2R7-505 features nickel-plated copper tabs for electrical connection. Soldering should be performed using a temperature-controlled iron set to 350°C maximum with soldering time limited to 3 seconds per tab. Use rosin-core solder (SN63/PB37 or lead-free SAC305) with RMA flux. Pre-tinning the tabs before final assembly is recommended. Avoid applying excessive heat or mechanical stress to the cell body during soldering. The aluminum laminate package is sensitive to heat - keep the iron tip away from the cell body. For high-volume production, resistance welding or laser welding of tabs is preferred over soldering. After soldering, allow the cell to cool to room temperature before applying power. Do not bend the tabs closer than 3mm to the cell body to prevent seal damage. Use appropriate ESD protection during handling and assembly.

For prototype quantities, hand soldering with temperature control is acceptable. For production volumes, consider welded connections or contact us for assembly recommendations.

The AW-PZ-2R7-505 offers distinct trade-offs compared to small lithium batteries for wearable applications. Advantages include: virtually unlimited cycle life (500,000+ vs 300-500 for small Li-ion), rapid charging (minutes vs hours), wide temperature operation (-40°C to +65°C), maintenance-free operation, and no safety concerns about fire or explosion. The thin form factor (2.5mm) is competitive with or thinner than equivalent capacity lithium polymer cells. Disadvantages include: lower energy density (0.005 Wh vs 0.1-0.2 Wh for similar-sized Li-ion), higher self-discharge (15-20% per day vs 1-2%), and voltage droop during discharge. For wearables with frequent charging opportunities (daily or more) and burst power requirements, supercapacitors excel. For devices requiring multi-day runtime between charges, batteries remain more suitable. Many wearable designs now use hybrid approaches combining both technologies.

Evaluate your device's charging frequency and runtime requirements. For daily-charged devices with burst power needs, the AW-PZ-2R7-505 is an excellent choice.