QS Motor QSJ138D-90
QS138 90H V3 Mid Drive Motor with Internal Gearbox — 4000W rated IPM PMSM inrunner with helical gear reduction. 138mm stator diameter, 90mm stack height, 5 pole pairs. Spline drive shaft output. Air cooled, IP67 waterproof. The gearbox version of the 90H for builders needing high torque at the output shaft.
In brief: 4000W mid-drive motor. 48–72V rated.
Specs verified May 29, 2026
Where to Find
Prices tracked across 2 sellersPrice History
Price History
Price changes tracked by the crawler
Current best price $404.06. Over the past 90 days: low $403.22, high $414.84, average $405.90 — about average.
- AliExpress - SiAECOSYS Electric Powertrain Store
All Records
10 price records in this period
| Date | Price | Shipping | Total | Change | Coupon | Rating | Sales | In Stock | Status |
|---|---|---|---|---|---|---|---|---|---|
AliExpress - SiAECOSYS Electric Powertrain Store(10 records) | |||||||||
| May 29, 202605:58 PM | $404.06 | — | $404.06 | $0.00 | — | — | — | No | active |
| May 28, 202604:15 PM | $404.06 | — | $404.06 | $0.00 | — | — | — | No | dead |
| May 27, 202605:36 PM | $404.06 | — | $404.06 | $0.00 | — | — | — | No | dead |
| May 25, 202610:02 PM | $404.06 | — | $404.06 | $0.00 | — | — | — | No | dead |
| May 18, 202609:08 AM | $404.06 | — | $404.06 | $10.30 | USSS12−$12.00 | — | — | Yes | active |
| May 16, 202609:07 AM | $414.36 | — | $414.36 | $0.00 | — | — | — | Yes | active |
| May 15, 202609:01 AM | $414.36 | — | $414.36 | $0.48 | SRUS02−$2.00 | — | — | Yes | active |
| May 14, 202609:07 AM | $414.84 | — | $414.84 | $0.25 | SRUS04−$4.00 | — | — | Yes | active |
| May 12, 202609:07 AM | $414.59 | — | $414.59 | $11.37 | SRUS50−$50.00 | — | — | Yes | active |
| May 1, 202604:52 AM | $403.22 | — | $403.22 | Initial | — | — | — | Yes | active |
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Specifications
Motor Design
- Design
- Inrunner PMSM
- Stator Diameter
- 138mm
- Stator Height
- 90mm
- Pole Pairs
- 5
- Shaft Type
- Spline
- Internal Gear Ratio
- 1:2.35
- Cooling
- Air
Performance
- Wattage
- 4000W
- Peak Wattage
- 13500W
- Rated Voltage
- 48–72V
- Rated RPM
- 4800
Electrical
- Flux Weakening RPM
- 7000RPM
Features
- PAS Sensor Type
- None
- Temp Sensor
- KTY83
- Has Encoder
- No
Physical
- IP Rating
- IP67
Ports & Connectors
Phase Wires3 Ring Terminals
Motor Phase
| Pin | Wire color | Function |
|---|---|---|
| 1 | Yellow | Phase A |
| 2 | Green | Phase B |
| 3 | Blue | Phase C |
Hall Sensor
Hall Sensor
| Pin | Wire color | Function |
|---|---|---|
| 1 | Red | 5V Power |
| 2 | No color | None |
| 3 | Black | Ground |
| 4 | Green | Hall A |
| 5 | Yellow | Hall B |
| 6 | Blue | Hall C |
