You'd need a huge battery to power a camera for that long, as well as enough storage to match.
Let's assume something at the low end of the quality scale, e.g. 1Mbps 480p H.264; that's 125KB/s, or roughly 11TB for 3 years of video. Likewise, take 5W as an average power consumption. 5W for 3 years turns out to be around 130kWh, which is a large capacity even for an EV battery. For comparison, the largest Tesla has 100kWh.