I'm thinking about taking the plunge into my next upgrade for a box mod...I want something in the 80 watt and up range and was looking into the Sigelei 100 Watt Plus and the Sigelei 150 Watt any thoughts on these two? I've heard a lot about the 150 watt having problems with the firing button? Also my second question, the box mods I have now have built in batteries so I've never had a need to purchase batteries or battery chargers...What kind of batteries would you guys recommend to run something like the two box mods I mentioned? Is it wise to have a battery charger, what kind?