This is from their Q&A section on the website:
That being said I would like a concrete yes/no on just leaving it on the charger.
edit:
Just spoke with the customer service duder through their online chat here's the transcript:
So looks like were good to go to leave them on the base...
Just got mine in, waiting with baited breath for the light to turn green :)
Edit: Do have one big question, is it OK if I leave it on the charger when not in use? Don't want to risk hurting battery life.
Also for SliM, I don't have a problem at all hitting the button seems to work fine for me