Best Practice for Charging Spare Battery

Best Practice for Charging Spare BatteryI know that with lithium batteries your charging routine can impact battery life.I have two batteries. When it's time to replace the active one, I exchange it with the spare.What's the best practice with the spare when it comes to extending its life? I can think of three possible options:1. Leave it charging until it's needed.2. Leave it discharged until shortly before needed and charge it then.3. Charge it right after removal from the doorbell. Then do a "touch up" charge right before use.Thanks.