I've been looking into buying one of these pens since I'm making the switch from flowers to wax, but i have a few questions 1. How much can you pack into the new k.i.s.s carts, and how good are they? 2. How long does the battery on the o-phos last and how long does it take to charge from full 3. Are these pens the best choice when it comes to concentrates for this price range ($50-90)? Sent from my iPhone using Grasscity Forum