Why would a Chevrolet 2017 Volt need a battery replacement after one year?

Hello, which battery was replaced? CARFAX is probably speaking about the 12 volt battery under the hood, not the hybrid battery. A 12 volt battery can fail for a multitude of reasons, or just be replaced because someone left the lights on and depleted it. CARFAX does have some valuable data, but is extremely general in work description. And, it is not entirely complete -- not all shops report to CARFAX.