I really want 80% limit feature on TWS earphones. It has small battery, perhaps fully utilize battery capacity for longer battery life, harder to replace batter

I really want 80% limit feature on TWS earphones. It has small battery, perhaps fully utilize battery capacity for longer battery life, harder to replace battery (especially with waterproof). I'd like to have a 80%-100% slide switch on the case, but it would be too nerd feature.