Yep I'm using Thunder Power Pro lite V 2 so now were do I get an adapter? at what rate should I charge at?
Does your pack specify a charge rate? A few years ago that would have been a 1C charge, but most packs these days allow a faster charge through as long as there is simultaneous monitoring/balancing of the individual cells.
I would be surprised that if your packs are new, that you couldn't at least charge at 2C--but of course check it out first.
added:
I just checked DraganFly (aka rctoys), and they claim you can charge the Thunderpower Pro lites at 3C. So if you have 3900mAHr packs, that would be about 11.7 amps. However if this is a 4s pack, then you are outputting 175 watts, and I am not sure your charger can output that many watts.
I also note that the prices have dropped too. The 4s2100 pack is ~$70, not that different than the FMA 4s2100 packs I bought 2 years ago. I don't think they are as quite as light as the older FMA 2100 or Thunderpower lite 2000 packs though.