What to Do When Water Gets Into Your Electric Vehicle Motor

Water ingress is one of the most common — and most avoidable — killers of electric vehicle motors. On rainy days a scooter or e-bike is often left parked outside, and water can find its way into the motor through the axle seals or cable entry. If the motor is then run while wet, the moisture can cause an internal short circuit and burn the windings. Here is what to do when it happens.

Quick Diagnosis After Water Exposure

The electric drive motor is the core component of the vehicle, so treat any suspected water ingress seriously. First, park the vehicle aside and let it rest for a few hours. If the vehicle then operates normally, the motor has likely dried out on its own and no further action is needed. If performance is erratic, do not keep riding — continued operation with wet insulation can permanently damage the windings.

Removing the Moisture

If the motor does not run cleanly, you have two options:

• Disassemble and dry: open the motor and remove the moisture inside, taking care to keep dust and debris away from the magnets and windings.
• Professional service: take the vehicle to an after-sales service department and let a technician dry and test the motor properly. This is the safer route if you are not equipped to open a hub motor.

Know Your Motor Type

The right handling also depends on the motor type. Brushed high-speed motors are efficient with strong starting torque, but they output power through a reduction gearbox and are noisier. Brushless low-speed gearless motors are maintenance-free and quiet, though their controllers are more complex and their starting current is higher. Brushed low-speed gearless motors are simple and cheap, but weak on starts and climbs and heavier on power consumption.

Prevention is always cheaper than repair: check axle seals after wet rides, avoid high-pressure washing around the motor, and let the vehicle dry before charging or riding hard. Looking for a replacement? Browse our moped and scooter motors or order EV parts such as seals, cables and controllers from our catalog.