Used EV residuals sliding while registrations climb

Been tracking used prices for a few months now and the gap keeps widening. A three-year-old compact EV that listed around 38k is fetching roughly 15k at auction, while the equivalent petrol model still holds near 20k. New registration figures keep rising, so market share looks healthy on paper, but trade-in values are soft and dealers are getting cautious. Is this just oversupply from leasing returns landing all at once, or are private buyers genuinely wary of battery health and charging costs? Curious what others are seeing locally,