The ETENWOLF S4 is a dual-motor electric pump designed for SUP paddleboards, inflatable kayaks, wing foils, and air mattresses. It operates on DC 12V via a car cigarette lighter socket and uses a two-stage inflation system: Stage 1 delivers 600 L/min high-volume flow to fill the body fast, then automatically switches to Stage 2 at 70 L/min for precise high-pressure finishing. A standard 11 ft SUP paddleboard (0 to 12 PSI) inflates in 6 minutes 17 seconds. This pump does not connect to tire valves and cannot inflate car or bike tires — its 20 PSI maximum is designed exclusively for low-pressure inflatable watercraft and recreational equipment.
600 L/min
Stage 1 Airflow
70 L/min
Stage 2 Airflow
20 PSI
Max Pressure
6 min 17 s
11 ft SUP 0→12 PSI
±0.5 PSI
Pressure Accuracy
DC 12V
Power Supply
20 PSI Max Pressure & ±0.5 PSI Accuracy
The S4 operates across a 1.5–20 PSI range — the correct pressure window for inflatable watercraft, wing foils, and recreational inflatables. Pressure accuracy is ±0.5 PSI across the full range (measured at 5, 10, 15, and 20 PSI). The auto-stop feature cuts inflation precisely at the preset target. An overpressure protection circuit triggers at 22 PSI and displays error code E22, preventing any over-inflation of the connected item. The 20 PSI ceiling is a deliberate design limit: the S4 does not have car tire valve adapters and cannot be used to inflate vehicle tires.
Dual-Stage Inflation: 600 L/min → 70 L/min Auto-Switch
The S4’s two-stage system is its core performance feature. Stage 1 runs both motors simultaneously at 600 L/min to rapidly fill the large internal volume of a paddleboard or inflatable boat — this is the fast-fill phase where most of the air goes in. When internal pressure exceeds 0.7 PSI for 5 consecutive seconds, the system automatically switches to Stage 2: a single motor at 70 L/min that brings pressure up precisely to the target. This auto-switch eliminates manual mode selection and prevents the abrupt pressure jumps that can damage inflatable seams. The result is the tested 6 minutes 17 seconds for an 11 ft SUP from 0 to 12 PSI at 25°C.
| Stage | Airflow | Trigger Condition | Purpose |
|---|---|---|---|
| Stage 1 (High Volume) | 600 L/min | Start — until pressure > 0.7 PSI for 5 s | Rapid body fill |
| Stage 2 (High Pressure) | 70 L/min | Auto after Stage 1 | Precise pressure finish |
Inflation Times
All inflation times are measured at 25°C ambient with the vehicle engine running. The 11 ft SUP result (6 min 17 s, 0→12 PSI) is a factory-confirmed figure. Times for larger inflatables such as two-person kayaks (approx. 400 L volume) will be proportionally longer and depend on target pressure. The 3-metre power cable with cigarette lighter plug provides enough reach from the car’s front seat to the roof rack or beach-side loading area.
| Item | Volume (approx.) | Start PSI | Target PSI | Inflation Time |
|---|---|---|---|---|
| 11 ft SUP paddleboard | ~200 L | 0 | 12 | 6 min 17 sec |
| 2-person inflatable kayak | ~400 L | 0 | 10 | Data pending |
| Single air mattress | ~50 L | 0 | 1.5 | Data pending |
| Double air mattress | ~100 L | 0 | 1.5 | Data pending |
DC 12V Power & Cable
The S4 draws power from a standard 12V car cigarette lighter socket at up to 10A maximum current draw. It works with any vehicle that has a 12V accessory socket — no minimum battery specification beyond the standard cigarette lighter socket requirement. Running the vehicle engine during use is recommended to avoid draining the car battery during extended inflation sessions. The power cable is 3 metres long with a cigarette lighter plug, giving sufficient reach from the vehicle’s socket to the load area or beach-side unloading spot.
| Parameter | Value |
|---|---|
| Power supply | DC 12V (car cigarette lighter) |
| Max current draw | 10A |
| Cable length | 3 metres |
| Plug type | Cigarette lighter (12V accessory) |
| Engine running recommended | Yes |
Noise Level
Factory noise measurement at 1 metre distance: 90.9 dB(A) on sample 1 and 90.3 dB(A) on sample 2. This is expected for a dual-motor 600 L/min pump and is comparable to other high-volume electric SUP pumps in this class. For context, 90 dB(A) is approximately equivalent to a lawnmower at 1 metre. Use in open outdoor environments (beach, lakeside, car park) keeps ambient noise levels acceptable; indoor use in small spaces is not recommended due to the volume.
6 Included Nozzle Adapters
The S4 includes 6 nozzle adapters covering the main valve types used in inflatable watercraft, recreational gear, and outdoor equipment. Each nozzle is designed for a specific valve family — using the wrong nozzle can cause air leakage or valve damage, so matching the nozzle to the item is important.
| # | Nozzle Name | Compatible Items |
|---|---|---|
| 1 | SUP / Paddleboard Nozzle | SUP paddleboards, inflatable tents |
| 2 | Inflatable Boat Nozzle | Rubber dinghies, inflatable rafts |
| 3 | Vacuum Nozzle | Vacuum storage bags |
| 4 | Air Mattress Nozzle | Inflatable mattresses, sleeping pads |
| 5 | Wing Foil Nozzle | Wing foils, kite surfing kites |
| 6 | Ball / Ring Nozzle | Swimming rings, yoga balls, inflatables |
Technical Limits & Important Restrictions
The S4 is a low-pressure, high-volume pump. It is not a tire inflator and has no tire valve adapters. Attempting to inflate car or bicycle tires with the S4 is not possible — the nozzle set does not interface with Schrader or Presta valves. For tire inflation, the ETENWOLF S3 (22 L/min, 160 PSI) or S1 (20 L/min, 160 PSI) are the correct products.
| Condition | Behavior |
|---|---|
| Pressure exceeds 22 PSI | Overpressure protection triggers; displays E22 error |
| Car tire inflation | Not possible — no tire valve adapters included |
| Bicycle tire inflation | Not possible — no Schrader/Presta valve adapters |
| Engine off during use | Functions normally; may drain car battery in extended use |
| Max operating pressure | 20 PSI |
Compatible Applications
The S4 is designed for all inflatable items in the 1.5–20 PSI pressure range. Its 600 L/min Stage 1 flow rate makes it fast enough for large-volume inflatables that would take impractically long with a hand pump or small electric pump. Items requiring over 20 PSI — including all vehicle tires, road bikes, and any high-pressure sports equipment — are outside the S4’s operating range.
| Application | Typical Pressure | S4 Compatible |
|---|---|---|
| SUP paddleboard (all-round) | 12–15 PSI | Yes |
| SUP paddleboard (race/touring) | 15–20 PSI | Yes |
| Inflatable kayak / dinghy | 2–10 PSI | Yes |
| Wing foil / kite surf kite | 7–12 PSI | Yes |
| Air mattress (camping) | 0.5–2 PSI | Yes |
| Swimming ring / pool float | 1–3 PSI | Yes |
| Yoga / exercise ball | 1–3 PSI | Yes |
| Car tire | 30–45 PSI | No — use S1/S3 |
| Road bicycle tire | 80–130 PSI | No — use S1/S3 |
Frequently Asked Questions
How long does the S4 take to inflate an 11 ft SUP paddleboard?
6 minutes 17 seconds from 0 to 12 PSI, tested at 25°C with the vehicle engine running. This uses the automatic dual-stage sequence: Stage 1 at 600 L/min fills the board body, then Stage 2 at 70 L/min brings pressure to the target. No manual mode switching is needed.
Can the S4 inflate car or bicycle tires?
No. The S4 has a maximum pressure of 20 PSI and does not include Schrader or Presta valve adapters. Car tires require 30–45 PSI and bicycle tires require 25–130 PSI — both beyond the S4’s capability. For tire inflation, use the ETENWOLF S1 or S3.
What is the difference between Stage 1 and Stage 2, and how does the switch happen?
Stage 1 runs both dual motors at 600 L/min for rapid high-volume filling. Stage 2 uses a single motor at 70 L/min for precise pressure control in the final phase. The switch is automatic: when internal pressure exceeds 0.7 PSI continuously for 5 seconds, the pump switches to Stage 2 without any user input. This design protects inflatable seams from pressure shock and ensures accurate final pressure.
Do I need to run the car engine while using the S4?
Running the engine is recommended. The S4 draws up to 10A at 12V — prolonged use with the engine off can drain a standard car battery, particularly for larger inflatables. For a single SUP inflation (about 6 minutes), most healthy car batteries can handle it with the engine off; for multiple inflatables in sequence, run the engine.
What do the 6 nozzles fit?
The 6 nozzles cover: (1) SUP paddleboards and inflatable tents, (2) rubber dinghies and inflatable rafts, (3) vacuum storage bags, (4) air mattresses and sleeping pads, (5) wing foils and kite surfing kites, (6) swimming rings and yoga balls. Each nozzle is labelled and shaped for its specific valve type — match the nozzle to the valve before inflating.
How loud is the S4? Can I use it in a quiet campsite?
Factory-measured noise is 90.3–90.9 dB(A) at 1 metre under load — approximately equivalent to a lawnmower at close range. Inflation of an 11 ft SUP takes about 6 minutes. In open outdoor environments (beach, lakeside) this is generally acceptable. In a quiet campsite where neighbours are within 10–15 metres, the noise may be noticeable. Consider inflating before arriving at the campsite if noise is a concern.
What happens if pressure exceeds 20 PSI?
The S4 has an overpressure protection circuit that triggers at 22 PSI, displaying error code E22 and stopping inflation. The preset maximum target of 20 PSI prevents reaching this threshold in normal use. The 22 PSI protection acts as a hardware safety backup for cases where valve connections are loose or the wrong nozzle is used.
