That's what I'm trying to figure out. I have seen some batteries that say the have the circuit, and then some that are listed as ICR but make no mention of having a protective circuit?
ICR batteries come with and without protective circuits. The difference between IMR and ICR is that IMR use a safer chemistry than ICR (seeing as IMR are LiMn and ICR are LiCoO2). Also IMR batteries are high drain, capable of handling more amps and delivering more power which is definitely needed the higher wattage you go (or the lower ohms you build).