I rule it that it drains when it's being used - which for me means wielded. It won't drain being in the bag, backpack or at cart. But if you use it - you get drained that quarter when you used it.
Oh, that’s too nice. The power of the scepter is too much to carry, ready to use at all times, without the cost! Great power comes at a cost. I would, however, let them have the scepter in a cart, or on their mule, without being drained...
Why too nice? If it drained them like all the times they would probably just throw it away. I would if I had something that drains my stats in game where average stat is 3.... Not worth the price.
This way it has cost but it's useful. No point giving players something they won't use. I may be too nice, but I also like to have opportunity to also play with items I give players. If they won't use it at all or just throw it away - I won't have my share of fun too.
Of course, each table play as they want, but I really don't care that much about throwing stones in front of my players as to give them more opportunities to have some epic moments and stories. I have different style it seems