I’ll be trustworthy: I under no circumstances left them on for eight hrs in a very row, but I do know someone with the WF-XM4s who sleeps with them in and advised me they'd last a full night – and also the XM5 battery life is purportedly improved. They are https://allhealthmarket.com/product/smart-wearables/smart-electronics-smart-wearables/headsets/lenovo-lp40-pro-thinkplus-earphones-tws-bluetooth-5-1-wireless-sports-headphone-waterproof-sport-noise-reduction-headphones-touch-control-250mah/