Laptop should be fine as long as u seal it in a way that its 'dust-proofed' - a few plastic bags should do the trick.
Batteries are a bit tricky but one thing's for sure: never leave them discharged too long, they'll lose their capacity considerably more. Keeping them fully charged for a long time does slowly reduce their capacities but its no where near as bad compared to leaving diacharged completely.
I always leave my laptop at 50% when I travel away and when I come back I don't see much loss in capacity, if at all.
Finally, I'd disconnect it from the laptop.
As a side note, don't leave them for longer than 4-6 months.
Good luck