New Delhi, May 12 -- Exploding sales of low-speed electric scooters-powered heavily by cheap Chinese imports-are giving a headache to India's established electric vehicle (EV) makers, who warn that the poor-quality products risk hurting consumer confidence in electric two-wheelers just as the sector is gaining scale.

Low-speed scooters-with speeds capped at 25 kmph-do not need to be registered on the Vahan portal, and so their growth has gone under the radar. But industry estimates point to sales numbers matching that of established players such as TVS Motor Co., Bajaj Auto, Ola Electric Mobility, and Ather Energy, among others.

According to two-wheeler consultancy InsightEV, sales of low-speed electric scooters shot up more than 200% i...