Can I keep the Mars 2 plug in even if it’s fully charge?
Yes, the built in electronic system will protect the battery from damage.
It is recommended to unplug devices once these are fully charged or when not intended to use / not used for long time - this is true for Mars II and any other electronics with battery.
Agree but more nuanced is:
- if you can keep it charged then do so, frequent use of the battery will age it faster, use the mains whenever possible, battery only when no mains.
- if you intend to not use it for month, then let it drain to around 60% charge before storing.
- always keep at room temperature.
- if storing for a long time, fully recharge, use, fully discharge every 3 months.
In the specific case of the Capsule Max, I expect a substantially better product will emerge before the battery ages so I’d not worry about the battery, I’d suggest use it regularly, enjoy it, don’t worry about charging or battery, so it gives as much joy possible before the substantially better product appears.