The ETENWOLF S1 is a compact cordless tire inflator built specifically for Class A/B sedans. It delivers 20 L/min airflow and reaches 160 PSI max pressure in a 525 g package measuring 94 × 76 × 40 mm — small enough to live in a glove compartment, powerful enough to inflate a 195/65R15 sedan tire from flat to 35 PSI on a single charge.
20 L/min
Max Airflow
160 PSI
Max Pressure
5,200 mAh
Battery
525 g
Weight
±1 PSI
Accuracy
3 Tires
Per Charge
160 PSI Max Pressure, ±1 PSI Accuracy Verified Across Full Range
The S1 reaches a verified maximum of 160 PSI, confirmed with a calibrated digital pressure gauge. Accuracy across the entire operating range is ±1 PSI — tested at seven pressure points (20, 35, 50, 80, 100, 130, and 160 PSI) with three readings at each point. For sedan tires, a 3–4 PSI deviation from the recommended pressure measurably affects fuel economy and tire wear — this level of consistency matters.
20 L/min Airflow — 3 Sedan Tires on One Charge
At 0 PSI no-load (ambient 25°C, calibrated flow meter, 10 s stable), the S1 delivers 20 L/min. Real-world tests at 25 ± 2°C, battery at 100%, with supplied hose confirm three complete inflation cycles on a 195/55R15 from 0 to 35 PSI per charge. Sized and tuned for Class A/B vehicles: Nissan Sylphy, VW Lavida, Toyota Corolla, Honda Civic.
| Inflation Test Data — 25 ± 2°C, Battery 100%, Supplied Hose | ||
|---|---|---|
| Tire Size | Start PSI | Target PSI |
| 195/65R15 sedan | 0 | 35 |
| 205/55R16 sedan | 0 | 35 |
| 215/55R17 sedan | 0 | 35 |
| 195/65R15 sedan | 28 | 35 |
| 205/55R16 sedan | 28 | 35 |
| 215/55R17 sedan | 28 | 35 |
| 700C × 25C road bike | 0 | 100 |
4 Preset Modes with Auto-Shutoff
The S1 ships with four preset modes: Car (35 PSI), Bicycle (22 PSI), Basketball (8 PSI), and Custom (default 30 PSI, user-adjustable). Each mode auto-stops at the target pressure. A 700C × 25C road bike tire from 0 to 100 PSI takes 1 minute 33 seconds on a full charge — approximately 9 top-up cycles per charge on that size.
5,200 mAh — Full Charge in 2 h 38 min
Tianpeng lithium cell, 5,200 mAh / 19.24 Wh, charged via PD USB-C at 10W. Full charge time from 0%: 2 hours 38 minutes. Charge-while-inflate is not supported — simultaneous operation reduces available voltage and lowers efficiency. Below 20% battery, inflation speed drops slightly but max pressure stays unchanged at 150 PSI.
Noise: 80.8–84.8 dB(A) at 1 m
Measured across three production samples at 1 m from the front face, background noise below 30 dB(A), under simulated 35 PSI back-pressure (sedan tire working load). Sample 1: 84.8 dB(A), Sample 2: 80.9 dB(A), Sample 3: 80.8 dB(A). Equipment: calibrated sound level meter.
Technical Limits & Verified Edge Cases
ETENWOLF tested the S1 at the boundaries most manufacturers skip. Results below are from actual engineering tests, not estimates.
| Continuous run to thermal cutoff | Throttle valve at 35 PSI, 100% → 0% battery. No thermal protection triggered. No faults. |
| Cold soak −10°C / 2 hours | Normal startup and operation. Inflation speed slightly reduced. Max pressure unaffected. |
| Battery below 20% | Speed slightly reduced. Max pressure unchanged — still reaches 150 PSI. |
| Long-term storage | Store at 100%. Max 36 months. Top-up every 12 months. Confirmed starts normally after 36 months. |
| Operating temp range | −20°C to +60°C |
Compatible Vehicles & Applications
The S1 is built for compact sedan drivers, motorcycle riders, and cyclists who need a pocketable inflator. It is not suitable for mid-size SUVs or larger.
- Sedans: Nissan Sylphy, VW Lavida, Toyota Corolla, Honda Civic
- Motorcycles: YAMAHA, HONDA, SUZUKI
- Bicycles: Giant, Merida, Cannondale
- Not recommended: Mid-size SUVs → use S3 or S5. Full-size SUV/pickup → use S5, S6, S7.
S1 vs S3: Which One Do You Need?
Same 160 PSI ceiling and ±1 PSI accuracy. The S1 is lighter and smaller for sedans. The S3 carries more battery and airflow for SUVs with larger tire volumes.
| Parameter | S1 | S3 |
|---|---|---|
| Max Airflow | 20 L/min | 22 L/min |
| Battery | 5,200 mAh | 7,800 mAh |
| Weight | 525 g | 1,050 g |
| Dimensions | 94 × 76 × 40 mm | 134 × 98 × 174 mm |
| Best for | Class A/B sedans | Mid-size SUVs → S3 |
Third-Party Certifications
All certifications issued by independent third-party laboratories. Report numbers provided for traceability.
| Certification | Report No. | Issuing Body | Date |
|---|---|---|---|
| CE (EMC + LVD) — EU CE Marking | WTH25H12333145E | Shenzhen Walter Inspection Group | 2025-12-25 |
| FCC — FCC Equipment Authorization | WTH25H12333147E | Shenzhen Walter Inspection Group | 2025-12-25 |
| UN38.3 | WTH25D12333150B | Shenzhen Walter Inspection Group | 2026-01-13 |
| MSDS | WTH25D12333150B001 | Shenzhen Walter Inspection Group | 2026-01-13 |
| RoHS — EU RoHS Directive | WTH25X12333148C | Shenzhen Walter Inspection Group | 2026-01-14 |
| Design + Utility Model Patent | — | China NIPA | Active |
| IDEA Design Award | — | IDSA | — |
Frequently Asked Questions
How many sedan tires can the S1 inflate on a full charge?
3 tires. Tested on 195/55R15, 0 → 35 PSI at 25°C. A fourth tire may not reach target pressure. For 4 full inflations per session, use the S3 (7,800 mAh).
How long to inflate a bicycle tire?
700C × 25C from 0 to 100 PSI: 1 minute 33 seconds on a full charge. Approximately 9 top-up cycles per charge.
S1 vs S3 — what is the difference?
S1 (20 L/min, 5,200 mAh, 525 g) for Class A/B sedans. S3 (22 L/min, 7,800 mAh, 1,050 g) for mid-size SUVs like RAV4 or CR-V.
Does the S1 work at −10°C?
Yes. After 2-hour cold soak at −10°C: normal startup, slightly reduced inflation speed, max pressure unaffected. Operating range: −20°C to +60°C.
Can the S1 charge while inflating?
No. Simultaneous charging and inflating reduces available voltage and lowers efficiency. Charge fully before use.
How accurate is the pressure gauge?
±1 PSI full range. Verified at 7 points (20, 35, 50, 80, 100, 130, 160 PSI), 3 readings each. Full-range accuracy, not a best-case figure.
Is the S1 CE and FCC certified?
Yes. CE: WTH25H12333145E. FCC: WTH25H12333147E. Both issued 2025-12-25 by Shenzhen Walter Inspection Group. UN38.3: WTH25D12333150B. RoHS: WTH25X12333148C.
