Selection and matching of batteries, motors, and propellers for quadcopter drones

Here’s a field-tested, bilingual guide to matching batteries, motors, and propellers for quadcopter drones. It’s practical, math-light (but precise), and comes with worked examples.

Quadcopter power-train selection (battery × motor × prop)

1) Start with mission & weight

• Mission: acro/racing, cinematic/photography, long-range, or heavy-lift.

• All-up weight (AUW): frame + electronics + battery + payload.

Rule of thumb thrust-to-weight (TTW):

• Cinematic / mapper: ~2.0–2.5 : 1

• Long-range cruiser: ~2.2–3.0 : 1

• Freestyle / racing: ~3–5 : 1

• Heavy-lift (gimbals, sensors): ~2.0–2.3 : 1

Per-motor max thrust target:

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(Using grams for convenience is fine.)

2) Choose propeller diameter & pitch first

• Diameter (D): sets disk area → efficiency & hover current. Bigger D = lower disk loading = longer hover, but needs lower KV (slower rpm) and more torque.

• Pitch (P): sets “pitch speed” ≈ how fast air is accelerated. Higher P = more speed/response, more current.

• Blade count: bi-blade = efficient/quiet, tri-blade = better grip/response (typical on 5"), quad-blade = niche/high-grip.

Useful quick checks:

• Total disk area A=4×π(D/2)². Lower AUW/A → better efficiency.

• Pitch speed (mph) ≈ (P(in)×RPM)/1056​. Don’t overshoot your mission speed.

• For sizing:
  3" micro, 5" acro, 7" long-range, 9–10"+ heavy-lift are the common “sweet spots”.

3) Pick motor stator size & KV to match the prop and battery voltage

• Stator size: e.g., 2207 = 22 mm diameter, 7 mm height. Bigger stator = more torque = can swing bigger/higher-pitch props with less heating.

• KV: RPM per volt no-load. Under load, RPM ≈ KV × V × η (η≈0.75–0.9).
  Lower KV for large props/high voltage; higher KV for small props/low voltage.

• Use manufacturer thrust curves (motor+prop+battery) to confirm thrust and current at 50–100% throttle.

4) Select battery: cell count (S), capacity (mAh), and C-rating

• Voltage: 4S (≈14.8 V) for micros/3–4", 6S (≈22.2 V) mainstream for 5–7", 6–8S for 9–12"/heavy-lift.

• Capacity: balances endurance vs weight. LR likes Li-ion (energy-dense, lower current). Acro/HL uses LiPo (high current).

• C-rating: Required C≈I_max/Capacity(Ah) ​​. Treat vendor C as optimistic; design for ~70% of the claim.

• Usable capacity: plan on ~80% of nominal to protect packs.

Flight-time estimate:

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5) ESC & wiring

• ESC current rating: ≥ 1.2–1.5× your per-motor peak current from the thrust curve. Thermal headroom matters.

• Quality connectors (XT30/XT60/AS150), short leads, and low-ESR capacitors on the PDB/ESC reduce voltage sag.

6) Validate the match

• Check thrust margin: does your chosen motor+prop do ≥ T_req per motor at ≤80% throttle? If not, pick more prop or more stator / less KV.

• Check current: per-motor peak current × 4 ≲ ESC & battery limits (with safety headroom).

• Maiden with current/voltage logging; adjust pitch and filters as needed.

Worked examples (ready-to-copy combos)

These are proven “lanes,” not brand-locked. Always verify with the motor’s thrust tables.

A) 5" Freestyle/Acro (6S)

• Target: AUW ≈ 650–750 g, TTW ≈ 3.5–4.5:1 → per-motor max thrust ≈ 600–850 g.

• Prop: 5×4.0–4.3×3 (tri-blade common).

• Motor: 2207 / 2306, 1600–1900 KV (for 6S).

• Battery: 6S 1300–1800 mAh LiPo, high C.

• ESC: 35–45 A (per motor) 4-in-1.

• Reality check: peak current ~30–40 A/motor; average ~20–30 A total in acro; 3–5 min typical.

B) 7" Long-Range (6S, efficient cruise)

• Target: AUW ≈ 1.0–1.3 kg, TTW ≈ 2.2–3.0:1 → per-motor ≈ 550–975 g.

• Prop: 7×3–3.5×2 (bi-blade for efficiency).

• Motor: 2507–2806.5, 1200–1600 KV (6S).

• Battery: 6S 3000–5000 mAh, Li-ion (cruise) or LiPo (punch).

• ESC: 30–45 A per motor.

• Reality check: cruise current often 12–18 A total; 15–25 min depending on weight, props, and throttle.

C) 3" Micro (4S)

• Target: AUW ≈ 200–300 g, TTW ≈ 3:1 → per-motor ≈ 150–225 g.

• Prop: 3×3×3 or 3×2.5×3.

• Motor: 1404–1507, 3500–4200 KV (4S).

• Battery: 4S 650–850 mAh LiPo.

• ESC: 12–20 A per motor.

• Reality check: avg 7–10 A total; 4–7 min.

D) 10" Heavy-Lift (Cine/Mapping)

• Target: AUW ≈ 2–3 kg, TTW ≈ 2.0–2.3:1 → per-motor ≈ 1.0–1.7 kg.

• Prop: 10×4–5 (bi-blade, low pitch for smooth thrust).

• Motor: 2812–3510, 500–800 KV on 6–8S.

• Battery: 6S 6000–10000 mAh LiPo (or dual).

• ESC: 40–60 A per motor.

• Reality check: avg 25–35 A total; 10–18 min with smooth flying.

Quick decision cheatsheet

• Need quiet & efficient hover → bigger diameter, lower pitch, lower KV, bi-blade.

• Need snap & top speed → smaller diameter, higher pitch, higher KV, tri-blade.

• Voltage choice: higher S = lower current for same power (less sag), but heavier packs and lower KV motors.

• Thermal sanity: motors <70–80 °C after hard pulls; if hotter, reduce pitch/prop or pick a larger stator.

• Safety margin: ESC ≥1.2–1.5× peak; battery C (×Ah) ≥ total burst current; prefer low-IR packs.