Usually the reason behind discharging fully once per month is because when this happens, the laptop records how much capacity is required to recharge the batter

Usually the reason behind discharging fully once per month is because when this happens, the laptop records how much capacity is required to recharge the battery. This will keep your battery % left accurate. The actual preference for getting the MOST DISCHARGES out of a lithium ion battery is discharging it to 50%. This, however, doesn't not to equate to longest battery life (in terms of age) for the use within a laptop/phone. Edit: There is something state of charge estimation models which may rely on this variable to decide how full they'll charge the battery. If you don't fully discharge and fully recharge the battery to update this capacity value, the SOC estimation model might overcharge the battery, thus decreasing the lifespan.