The ETENWOLF S3 is a cordless tire inflator engineered for continuous-duty inflation. Its brushless motor delivers 22 L/min airflow at 160 PSI with a verified 100% duty cycle — meaning it can inflate all four tires of a mid-size SUV back-to-back without pause, pause-to-cool, or performance drop. At 1,050 g with a 7,800 mAh battery, it is the inflator for drivers who need sedan-to-mid-SUV coverage in one unit.
22 L/min
Max Airflow
160 PSI
Max Pressure
100%
Duty Cycle
7,800 mAh
Battery Capacity
±1 PSI
Pressure Accuracy
1,050 g
Unit Weight
160 PSI Max Pressure & ±1 PSI Accuracy
The S3 operates across a 0–160 PSI range with a verified full-range accuracy of ±1 PSI. Pressure is measured at the preset target and the motor cuts automatically — no manual monitoring required. This accuracy is consistent across all common automotive pressure ranges: 30–36 PSI for sedans, 35–44 PSI for SUVs, and up to 80 PSI for light commercial vehicles. The 160 PSI ceiling also covers bicycle tires (road bike: 80–130 PSI, mountain bike: 25–35 PSI) and sports balls (6–15 PSI), making the S3 a single tool across vehicle classes.
100% Duty Cycle: Continuous Inflation Without Pause
The S3’s defining specification is its verified 100% duty cycle. In factory testing, the S3 inflated four consecutive car tires from 0 to 35 PSI in a total of 23 minutes with zero pause, no cooling required, and no thermal protection trigger. Most portable inflators operate at 30–50% duty cycle — they require 10–20 minute cool-down periods between tires. The S3 eliminates this entirely through its motor aging pre-treatment process: before shipment, every unit undergoes a full-discharge continuous run under 35 PSI back-pressure from a full battery to empty, confirming no thermal fault occurs. At below 20% battery, output decreases slightly as battery voltage drops — this is normal electrochemical behavior, not a fault condition.
22 L/min Airflow & Inflation Times
At 22 L/min (measured at 0 PSI back-pressure, 25°C ambient), the S3 delivers more than double the airflow of the S0 (15 L/min) and approximately half that of the S5 (42 L/min). For real-world reference: a 195/65R15 sedan tire (0→35 PSI) takes approximately 25 seconds; a 215/55R17 mid-sedan tire takes approximately 25 seconds; a 235/65R19 mid-SUV tire takes approximately 25 seconds. The full four-tire sequence (4 × 235/65R19, 0→35 PSI) completes in 23 minutes continuous.
| Tire Size | Use Case | Start PSI | Target PSI | Inflation Time |
|---|---|---|---|---|
| 195/65R15 | Compact sedan | 0 | 35 | ~25 sec |
| 215/55R17 | Mid-size sedan | 0 | 35 | ~25 sec |
| 235/65R19 | Mid-size SUV | 0 | 35 | ~25 sec |
| 4 × 235/65R19 | Full SUV set | 0 | 35 | 23 min (continuous) |
7,800 mAh Battery & Charging
The 7,800 mAh (28.86 Wh) lithium-ion battery uses Tianpeng cells and charges via USB-C PD at 15W. A full charge from 0% takes 3 hours 4 minutes. Pass-through charging (inflate while plugged in) is not supported. On a full charge, the S3 inflates approximately 3 sedan tires (195/65R15, 0→35 PSI) before capacity is exhausted. The Power Bank output provides USB-C at 15W and USB-A at 5V/2A — enough to charge a smartphone approximately twice. For long-term storage, factory recommendation is 100% charge state with a maximum shelf life of 36 months.
| Parameter | Value |
|---|---|
| Battery capacity | 7,800 mAh / 28.86 Wh |
| Cell brand | Tianpeng (天鹏) |
| Charge input | USB-C PD 15W |
| Full charge time | 3 h 4 min |
| Pass-through charging | Not supported |
| Power Bank output (USB-C) | 15W |
| Power Bank output (USB-A) | 5V / 2A |
| Phone charges per battery | ~2 |
| Tires per charge (195/65R15, 0→35 PSI) | 3 |
| Storage charge recommendation | 100% |
| Max storage duration | 36 months |
Noise Level
Formal noise measurement data (tested at 1 m, 35 PSI back-pressure, background <30 dB, A-weighting) has not yet been submitted by the factory. This section will be updated when calibrated measurements are available. For reference, compact cordless inflators in this airflow class typically measure 70–78 dB(A) at 1 m under load.
Technical Limits & Operating Conditions
The S3 is rated for continuous use on vehicles up to mid-size SUV class (e.g., Honda CR-V, Toyota RAV4, Ford Equator, GMC Terrain). For large SUVs, pickup trucks, and off-road vehicles such as the Ford Raptor, the higher-capacity S5 (42 L/min, 15,600 mAh) or S6 is recommended. In sub-zero environments below −10°C, the S3 will start and operate normally but inflation speed decreases due to reduced lithium-ion discharge performance at low temperatures — this is expected behavior, not a fault.
| Condition | Behavior |
|---|---|
| Battery below 20% | Slight output reduction (lower cell voltage); normal function continues |
| Temperature below −10°C | Reduced inflation speed; unit starts and operates normally |
| Large SUV / pickup from 0 PSI | Not recommended — use S5 or S6 |
| Pass-through (inflate while charging) | Not supported |
| Max operating pressure | 160 PSI |
Compatible Vehicle & Application Types
The S3 covers sedans, compact SUVs, mid-size SUVs, motorcycles, bicycles, and sports balls. Its 160 PSI ceiling and 22 L/min flow rate make it adequate for all passenger vehicle classes up to mid-SUV. It is not suited for full inflation from 0 PSI on large SUVs or pickups — those require the S5 or S6.
| Application | Typical Pressure | S3 Compatible |
|---|---|---|
| Compact / mid sedan (195/65R15–215/55R17) | 30–36 PSI | Yes |
| Compact SUV (Honda CR-V, Toyota RAV4) | 33–36 PSI | Yes |
| Mid-size SUV (Ford Equator, GMC Terrain) | 35–44 PSI | Yes |
| Large SUV / pickup (Ford Raptor, F-150) | 35–45 PSI | Not recommended |
| Motorcycle | 28–45 PSI | Yes |
| Road bike (700C) | 80–130 PSI | Yes |
| Mountain bike (27.5″) | 25–35 PSI | Yes |
| Sports balls | 6–15 PSI | Yes |
S3 vs S5 vs S6: Which Model to Choose
All three models support 100% duty cycle. The S3 (1,050 g, 22 L/min, 7,800 mAh) is sized for drivers of sedans and mid-SUVs who need a compact, pocketable inflator. The S5 (1,690 g, 42 L/min, 15,600 mAh) doubles the airflow and battery for large SUVs, pickups, and off-road vehicles. The S6 (2,750 g) adds camping and high-capacity use cases on top of the S5’s capability.
| Parameter | S3 | S5 | S6 |
|---|---|---|---|
| Airflow (max) | 22 L/min | 42 L/min | — |
| Max pressure | 160 PSI | 160 PSI | — |
| Battery | 7,800 mAh | 15,600 mAh | — |
| Weight | 1,050 g | 1,690 g | 2,750 g |
| Dimensions | 134×98×174 mm | 163×117×200 mm | 310×238×141 mm |
| Duty cycle | 100% | 100% | 100% |
| Best for | Sedan / mid-SUV | Large SUV / pickup | Large SUV + camping |
Certifications & Compliance
The S3 holds CE (EMC + LVD), FCC, UN38.3, MSDS, and RoHS certifications, all issued by Shenzhen Walter Inspection Group. Patent protection is registered with the China National Intellectual Property Administration (CNIPA) as a utility model patent.
| Certification | Report Number | Issuing Body | Date |
|---|---|---|---|
| CE (EMC + LVD) — EU CE Marking | WTH25H07183669E | Shenzhen Walter Inspection Group | 2025-07-22 |
| FCC — FCC Equipment Authorization | WTH25H07183671E | Shenzhen Walter Inspection Group | 2025-07-22 |
| UN38.3 (Lithium Battery) — UNECE TDG | LCSA02205295SA | Shenzhen Walter Inspection Group | 2025-03-25 |
| MSDS | A02205295SE | Shenzhen Walter Inspection Group | 2025-03-25 |
| RoHS — EU RoHS Directive | WTH25X07183749C | Shenzhen Walter Inspection Group | 2025-08-07 |
| Utility Model Patent | — | China NIPA | Active |
Frequently Asked Questions
What does 100% duty cycle mean on the S3?
100% duty cycle means the S3 can run continuously without stopping to cool down. In factory testing, the S3 inflated 4 consecutive car tires from 0 to 35 PSI in a total of 23 minutes with no pause and no thermal protection trigger. Most budget inflators operate at 30–50% duty cycle and require 10–20 minute rest periods between tires. The S3 eliminates this through motor design and a mandatory pre-shipment aging test that verifies each unit can sustain full-load continuous discharge without fault.
How long does the S3 take to inflate a Honda CR-V tire?
The Honda CR-V typically uses 225/65R17 tires at 33–36 PSI. Based on the S3’s 22 L/min airflow, a 0-to-35 PSI inflation takes approximately 25–30 seconds per tire. The S3 can inflate all four CR-V tires from 0 PSI in one continuous session without cooling breaks.
How many car tires can the S3 inflate on one charge?
On a full 7,800 mAh charge, the S3 inflates approximately 3 sedan tires (195/65R15, 0→35 PSI) before the battery is exhausted. Mid-size SUV tires (235/65R19) will yield fewer per charge due to higher volume. For a complete four-tire inflation set on an SUV, starting at 50% charge or higher is recommended.
What is the difference between the S3 and S5?
Both support 100% duty cycle. The S3 (7,800 mAh, 22 L/min, 1,050 g, 134×98×174 mm) is optimized for sedans and mid-size SUVs. The S5 (15,600 mAh, 42 L/min, 1,690 g, 163×117×200 mm) doubles both battery and airflow, making it the choice for large SUVs, pickup trucks, and off-road vehicles where S3 capacity would be insufficient.
Can the S3 charge my phone while inflating tires?
The S3 includes Power Bank output: USB-C at 15W and USB-A at 5V/2A. However, pass-through charging (charging the S3 while inflating) is not supported. Phone charging and tire inflation are separate functions — you can use Power Bank output after or before inflating, but not simultaneously with the compressor running.
Does the S3 work in cold weather below −10°C?
Yes — the S3 starts and operates normally below −10°C. Inflation speed will decrease because lithium-ion cells deliver lower discharge current at low temperatures. This is expected behavior, not a malfunction. For sub-zero use, allow the unit to warm slightly in a vehicle cabin before use for best performance.
How long does the S3 take to fully charge?
3 hours 4 minutes from 0% to 100% using a 15W USB-C PD charger. Standard 5W chargers will extend charge time significantly. The battery supports long-term storage for up to 36 months; factory recommendation is to store at 100% charge state.
