AQ1121 vs AQ1020: A Comprehensive Comparison of Underwater Propellers – Analysis of Thrust, FOC ESC Advantages and Application Scenarios
Posted by Fengyukun on
When choosing an underwater thruster, many users find themselves torn between the AQ1020 and its upgraded version, the AQ1121.
On the one hand, the AQ1020 delivers a thrust of up to 24 kg at 48V, which is even higher than the AQ1121’s 21 kg;
on the other hand, the AQ1121 is marketed as the ‘upgraded version’.
👉 So the question arises:
What exactly has been upgraded in the AQ1121? Is it worth choosing?
This article will help you fully understand the differences between the two by examining thrust, the control system (FOC), real-world user experience and application scenarios.
Product Overview
AQ1020 Underwater Thruster
The AQ1020 is a cost-effective, multi-purpose thruster:
24V → 10kg thrust
48V → 24kg thrust (high burst)
Built-in standard ESC
👉 Suitable for: kayaks / small boats / DIY projects / everyday use
AQ1121 Underwater Thruster (Upgraded Version)
The AQ1121 is a high-performance propeller designed to deliver stability and control:
Maximum thrust: 21 kg
Power: up to 2000 W
Built-in FOC ESC (upgraded core)
👉 Suitable for: extended operation / professional equipment / high-performance requirements
Key Specifications Comparison
| Feature | AQ1020 | AQ1121 |
|---|---|---|
| Voltage | 24V / 48V | 48V / 60V |
| Max Thrust | 24kg (48V) | 21kg |
| Power | Moderate | Up to 2000W |
| ESC | Standard ESC | FOC ESC (core advantage) |
| Control Feel | Basic | Ultra-smooth & precise |
| Positioning | High thrust output | Stable & efficient performance |
The Real Upgrade: FOC Control System
Many users focus only on thrust—but the real difference comes from:
👉 Motor control technology
FOC vs Traditional ESC: A True Generational Upgrade
| Aspect | AQ1020 (Standard ESC) | AQ1121 (FOC ESC) |
|---|---|---|
| Startup | Noticeable jerk | Ultra-smooth, no shock |
| Acceleration | Step-like | Linear and smooth |
| Noise | Higher | Significantly quieter |
| Precision | Basic | Excellent low-speed control |
| Efficiency | Standard | Higher efficiency, less power loss |
| Heat | Higher | Lower heat, more stable |
Why is FOC more important for underwater propulsion systems?
Characteristics of the underwater environment:
High water resistance
Rapid changes in load
Frequent need for low-speed control
Long operating times
👉 These are precisely the scenarios where FOC excels:
✔ Smoother operation → No sudden surges
✔ More energy-efficient → Longer battery life
✔ More stable → Less prone to overheating
✔ More precise → Precise control even at low speeds
Scenario Comparison (Helping You Choose the Right One)
Scenario 1: Kayaking / Leisure Use
👉 Requirements:
Simple propulsion
Occasional use
✔ Recommended: AQ1020
Reasons:
Sufficient thrust
Lower cost
Scenario 2: Requires High Thrust (Carrying Passengers/Loads)
👉 Requirements:
High power
Fast propulsion
✔ Recommended:
For burst power → AQ1020 (48V 24kg)
For stability → AQ1121
Scenario 3: Long-Duration Operation / Cruising / Commercial Use
👉 Requirements:
Long operating hours
Stable and reliable
✔ Highly Recommended: AQ1121
Reasons:
FOC is more energy-efficient
Lower heat generation
Less prone to performance degradation
The difference between the AQ1020 and AQ1121 is not essentially one of ‘strength versus weakness’, but rather a difference in ‘positioning’:
AQ1020 → High thrust, excellent value for money, suitable for most users
AQ1121 → Advanced control, higher efficiency, suitable for professional requirements
👉 If you’re only looking at thrust, the AQ1020 is already very powerful
👉 If you’re seeking a superior experience and stability, the AQ1121 is the true upgrade
FAQ
1: Why does the AQ1121 have lower thrust despite being the upgraded version?
Because the upgrades focus on the control system (FOC) and efficiency, rather than simply increasing thrust.
2: What exactly does FOC do?
It delivers smoother operation, greater energy efficiency and enhanced stability, making it particularly suitable for prolonged use and precise control.
3: Which model is better suited for kayaks?
The AQ1020 is sufficient.
4: Which model is better suited for professional equipment?
The AQ1121 is more suitable.