You can leave your charged lights on a charger without affecting the battery capacity.
Capsule lights have custom li-ion batteries that cannot overcharge and don't have memory effects like some older batteries. These batteries also include a protection circuit, so the battery will not fully discharge - this means even if the battery 'dies', it will still maintain a small charge.
Typically li-ion batteries have a lifespan of about 200 - 300 charge cycles / ~2 years.
Re. battery cycle: A battery cycle is one full discharge followed by a full charge. It does not have to happen all at once.
For example, if you run your capsule light battery down to 50% and then give it a full charge back up to 100%, then use the light again the next day and run it down to 50% and give it another full charge - this equates to 1x full charge cycle in this 2 day period.
Note: All batteries degrade over time and lose capacity, regardless of the type, usage, and storage conditions. Some conditions like temperature also affect the life cycle of a battery.
If you find that your lights are not holding a charge like the used to, or have a significantly diminished runtime, please contact us for a replacement.