Well, I don't own one of Intellect's packs, but pretty much any 7.4 volt LiPo you can treat as a 2 cell pack(as far as setting a charger, that is), & from what I've been told & read(as well as my own experience with my LiPos), you can easily charge them at what's called a 1 C rate, which is 1 amp per 1000mah of the pack's capacity. So with that 4000mah pack of yours, you should be able to charge it at 4 amps without any trouble at all. Just make sure the charger uses the CC/CV charge method(which is the charger starting at a constant current, & then when the pack's voltage reaches 8.4, it'll start lowering the current, to keep the voltage at 8.4, till the charge rate drops to 0, that's the proper way to charge any LiPo & what almost all LiPo friendly chargers use by default).....