Tools in This Collection
Battery Life Calculator
Calculate runtime from battery capacity and load current
Drone Flight Time Calculator
Estimate flight time from battery capacity and motor current draw
FPV Motor KV Calculator
Match motor KV rating to frame size and battery voltage
Decibel Calculator
Convert between dB gain/attenuation and power or voltage ratios
PCB Trace Width Calculator
Calculate minimum trace width for current and temperature rise
Power, RF, and Drone Electronics Workflow
Battery life, drone flight time, RF gain calculations, and PCB trace sizing are interconnected decisions in any power-constrained electronics project. Getting these numbers right before building saves both time and components.
Battery Life Calculation
Battery life is calculated from capacity and average current draw: Runtime (hours) = Capacity (mAh) / Current Draw (mA). But batteries don't deliver 100% of rated capacity in practice — efficiency factors apply. A 2,000mAh LiPo running a 500mA load has a theoretical runtime of 4 hours, but with an 85% efficiency factor, actual runtime is about 3.4 hours. The Battery Life Calculator applies the efficiency factor and outputs runtime at different load scenarios.
Drone Flight Time Estimation
Drone flight time depends on total battery capacity vs. average current draw from all motors. A typical 5-inch FPV quad with four 2306 motors draws about 30A total at hover (25A) to full throttle (60A+). With a 1,500mAh 4S battery at 25A average draw: runtime = 1,500/1,000 × 60min / 25A = 3.6 minutes of aggressive flying, or 5-7 minutes of cruising. The Drone Flight Time Calculator inputs motor count, average current per motor, and battery capacity to estimate flight time at different throttle profiles.
FPV Motor KV Selection
Motor KV rating (RPM per volt) determines the motor's speed and torque characteristics for a given battery voltage. Higher KV with smaller props = speed (racing); lower KV with larger props = efficiency (long-range). A 2306 2400KV motor on a 4S LiPo (14.8V nominal) spins at about 35,500 RPM no-load. On a 3-inch quad, this pairs with 3-inch props. On a 5-inch quad, you'd typically use 2206-2306 1700-2400KV depending on flying style. The FPV Motor KV Calculator matches KV to frame size and battery voltage.
Decibel Calculations for RF and Audio
Decibels express ratios on a logarithmic scale. For power ratios: dB = 10 × log₁₀(P2/P1). For voltage ratios: dB = 20 × log₁₀(V2/V1). A 3dB gain doubles power; a 6dB gain doubles voltage. An antenna rated at 5dBi has a power gain of 10^(5/10) = 3.16x over an isotropic antenna. The Decibel Calculator handles both power and voltage ratio conversions, which use different formulas and are a common source of confusion.
PCB Trace Width for Current Carrying
PCB copper traces must be wide enough to carry their rated current without excessive temperature rise. The IPC-2221 standard formula: Width = Area / (1.378 × copper weight). For an external trace carrying 2A with a 10°C rise on 1oz copper: required area is about 2.85 mils², width = 2.85 / (1.378 × 1) = 2.07 mils — approximately 52µm or 2 mil trace width minimum. The PCB Trace Width Calculator implements the full IPC-2221 calculation for both internal and external traces at any copper weight and temperature rise target.
Frequently Asked Questions
How do I calculate battery life for my electronics project?
Runtime (hours) = Capacity (mAh) / Current Draw (mA). A 2,000mAh battery powering a 400mA circuit runs for 5 hours theoretically. Apply an 80-85% efficiency factor for practical estimates: 5 × 0.85 = 4.25 hours actual runtime. For LiPo batteries in high-current applications (drones, RC cars), use 70-75% efficiency. The Battery Life Calculator includes the efficiency factor and handles unit conversions.
How long will my drone fly on one battery?
Flight time = battery capacity (Ah) × 60 min / average current draw (A). A 1,300mAh battery at 20A average draw flies for 1.3/20 × 60 = 3.9 minutes. Average current depends heavily on flying style: aggressive racing draws 2-4x more than smooth cruising. Measure your motor's actual current draw with a watt meter during your typical flying style for accurate estimates. The Drone Flight Time Calculator provides estimates at different throttle percentages.
What does PCB trace width affect?
Trace width determines how much current a copper track can carry without overheating. Too narrow and the trace resistancecauses heat build-up, voltage drop, and eventual failure — sometimes catastrophic in high-current applications like motor drivers and power regulators. The IPC-2221 standard defines minimum widths based on current, temperature rise, and copper weight (1oz vs 2oz copper). The PCB Trace Width Calculator computes the minimum safe width for your design.
Why do dB calculations use 10 log for power but 20 log for voltage?
Power is proportional to voltage squared (P = V²/R). Doubling voltage quadruples power. To make the dB scale consistent — where 3dB always means doubling — voltage ratios are multiplied by 20 (not 10) because 20 × log₁₀(2) = 6dB, which corresponds to 10 × log₁₀(4) = 6dB for the equivalent power doubling. Both formulas produce the same dB value when the impedance is the same, which is why the distinction matters most when comparing across different impedances.